The reason is because higher rank recipes stay orange longer, so you get guaranteed skill points longer. The rank 2 of this recipe turns yellow at 135, while the rank 3 is orange up to 145. The rank 3 also cost fewer materials, so you will save a lot of materials by getting the rank 3. You could actually level to 150 with the rank 2 recipe, but it will be green for the last 8 points, so you will have to spend a lot of extra materials, and there is no reason to rush 150, so I recommend to wait until you get the rank 3.
Changes were also made to levelling in earlier content with Legion's 7.3.5 patch. The level-scaling tech introduced in Legion not only be continued in the new continents of Kul Tiras and Zandalar, but was also be applied to content from prior expansions, allowing larger level brackets for lower level zones. Further, as previous expansions are now included in the base game, the level ranges for those expansions are now broadened, allowing players to spend more time leveling in preferred expansions and avoid others entirely. Some examples include a zone like Westfall having its level bracket (at 10–15 as of Legion) increased to 10–60, whilst continents such as Outland and Northrend sharing a 60–80 level bracket. The aim of this change is to encourage more player choice whilst levelling and to allow players to experience the full story of a particular zone without overlevelling the relevant quests.
Mythic+ has some similarity to raiding, but it’s designed for just five players, instead of the 10-to-30 that can make up a raid. This mode tasks players with clearing the game’s dungeons, but with specific changes that make them harder, scaling up until it’s impossible for groups to finish. Players receive a keystone in their inventory that assigns them their dungeon, one of the game’s 10, and gives the dungeon a level. This determines how difficult enemies are and what effects might make them harder. If the group completes the keystone in time, they get a new, higher-level stone; if they, don’t they get a lower-level stone.
-Gameplay- Gameplay has largely been stripped down to be a shell of its former self. This trimming has been going on for several expansions, but now it's even worse. Classes only have so many buttons which has resulted in very little skill involved in PvE (even PvP is a faceroll for most melee, lacking any sort of depth and decision-making as it's pretty clear what buttons to press in any given situation) and it's become more of a gear check. This expansion gave zero new abilities to classes, only took them away.
“I think that there’s a lot of gray in the game and in our world, right,” asked Cobo. “And so I think that tapping into that and making things reflect the complexities of the relationships that we have between these key characters and then the player itself, and having the player be able to experience that from their perspective, is really what is one of the strong connecting hooks of World of Warcraft.”
Today, I finally found out what the real problem was. I have always had the "Enable Zone Map" feature off, but noticed that I had "Enable Auto Zoom" still enabled. I assumed if you turned the map off, the auto zoom would just automatically not do anything. Turns out, every time I moved, the auto zoom was still collecting information and 'zooming' a map that didn't exist. I've turned it off now and my game is perfect - not a single slowdown. The difference is dramatic.
When you have completed your third zone, you should be nearly max level, but you still have work to do! Head back to your faction hub and complete the last foothold quest to unlock your fourth mission table champion. After, you will want to do your newly available invasion missions for your faction. This quest chain is one that will be time gated by reputation levels earned with the 7th Legion for the Alliance and iThe Honorbound for the Horde. Complete as many quests as you can and then finish up your leveling with side quests you may have left in previous zones as necessary.
A central problem of long-running MMOs like WoW is that the player's numbers have to continuously get bigger and bigger in order for the player to feel more powerful. When the original game released back in 2004, player health pools topped out in the thousands of hit points. Today, everyone is running around with absolutely massive numbers on their stat sheets, many of which have climbed into the millions. Players can deal out an equally massive amount of damage and it's gotten to the point where there are so many large numbers flashing across the screen during combat that it can be hard to keep track of exactly how well you are performing.
Both Zygor and Dugi guides are very in-depth in-game addons and they are very straightforward, yet extremely efficient to use with step-by-step instructions. The guides are being constantly updated to keep leveling and all the other guides at the most optimal rate, so you can use them for the latest Battle for Azeroth expansion! Zygor and Dugi guides are quite similar to each other, the only major difference being the GUI and a few features. Let’s have a closer look at the GUI differences.
The leveling guides on my site are essentially speed leveling guides.  My leveling guides are the same guides I use myself to speedrun to 60 on new servers to get 60 server first.  I list many occasions where I tell the player to "die on purpose" to go faster.  I tell the player to skip certain quests, because some quests are just not worth the time/XP.  I list tricks and shortcuts to go faster so you can reach level 60 much quicker.  I am still constantly going through them over and over again perfecting the guides to make them faster and easier to follow.  For the most part, the guide can be followed without the need from other player's help, as the whole guide was made from a solo run anyways.  Although I do list quests that can optionally be done if you have a group.

Dugi’s leveling guide is the leveling addon I’ve always used to level as fast as possible. It will show you where to go and what to do in-game, speeding up the leveling process. This is optional though, as the game already does a pretty good job at showing you where to go at all times. The addon does, however, come with a couple of other nice features and perks.