They have talked about streamlining some of the pre-expansion msq lines, especially the lv50 quests which filled out the end of 2.x.

Leveling is definitely much faster now; the advantage (and probable purpose) of this is to make it easier to reach the current expansion and level cap in the same amount of time, without having to resort to things like level jump items or starting all jobs at lv60.

Also: do you have a leveling buff on your server, or free company xp bonus, or an xp item equipped? If so then it will be even faster. You are probably getting the rested bonus as well, and in the future you will get the armoury bonus.

The good news is that you can try out multiple jobs and also not worry about leveling until you hit Shadowbringers. If you feel instances are too easy you can possibly try min ilvl sync.