Hiya,
I am a returning player and have been an avid fan since Guild Wars 1 and early GW2 beta's.
I'm going to keep this short without mega walls of text to explain the issues that I am seeing.
Mounts and not having them and in particular the Griffon and Skyscale make the maps that we see today more like a chore than enjoyment. I felt like I absolutely have to rush to get the flying mounts in order to not get frustrated with the extreme verticality throughout the maps. This goes for all of them since Heart of Thorns has been released. The verticality is so abundant to the degree that if you do not own one of these mounts or hell, even gliding. You are going to have a bad time in Guild Wars 2. This is my personal finding and you may have experienced it differently.
The level design is fantastic and I feel like a vibrant world has been created, however, sometimes there is just so much going on in the screen. This goes for events, meta events, hearts, special events in your HUD. It can get over crowded quick. Things like bouncy mushrooms to jump on and updrafts for your glider take away a lot of the beauty that I see when I look at the maps. They (again if you look at point 1) are a filler for making people overcome the insane verticality in this game. Map meta events and in particular the Dragonfall one have so much going on that it's basically a rush and go or get left behind. You have no idea whats going on when you are new to this and you absolutely need mesmer portals to even keep up.
For Path of Fire I enjoyed the story as lore, but found the order in which progress through maps and how we tackle them weird. I found myself going back and forth all over the place to do the story rather than in a single line up to bottom or left to right. In Guild Wars 1: Nightfall we went in a pretty easy and not so confusing pathway from Istan to the Desolation. You knew where the beginning and the endgame would be and that is miles better than what we are presented with today.
My feedback for End of Dragons is to seriously take a second look at your verticality and playable areas and where players have to progress through. I know from Guild Wars 1 that both Kaineng and the Echovald Forest will probably see massive amounts of verticality. Please do not push new players through agony. Not all players have Heart of Thorns or Path of Fire and the ones that do might not have the mounts. (I do have the Xpacs but did not have the Griffon or Skyscale, I am a WvW oriented player). If you put the same amount of obstacles through Cantha as you did in the previous expansions, you are hindering the fun and enjoyment that players could have in order to create locked gates and repetitive content that players may very likely not enjoy. (I thought the collections were cool until I had to do similar routes multiple times over for just slightly different collection items).
Fun and enjoyment better not be locked behind masteries.
All in all I would say Guild Wars 2 is still a big giant in the MMO scene and I regret not playing it more over the years. I always complained about the direction it took and have been wrong in some cases. However in my opinion, to the above named points I do not think I am wrong. Please consider my findings going forward. I do not expect radical changes or any at all, but keep in mind that verticality is cool, but often not fun.