What a missed opportunity....

No character growth. Literally.

What are you on about, there was plenty of character developement from those that mattered. X'D

bro I meant they somehow ironically and literally didn't age. Like there should haven been a time skip or something cuz lets just be rational for a sec how can a young teen go from a total qurikless loser to a pro hero in a mere time span of like a year ??? and where were the darn 2nd and 3rd yr students in UA all this time? Why only my boi deku's classmates suffering bruh-
I totally love this Manga but sometimes it just doesn't make sense???

Pretty sure there were multiple years inbetween the start and finish. More than one at least.
And there was plenty of training and level up arcs for all people involved. So I'm not sure how you think this went from zero to world hero within a short time and without anything happening. That makes it sound like you skipped reading most chapters and hence it feels random/quick to you. ╮(￣▽￣)╭
The 2nd and 3rd years were only mentioned in side-character ways here and there because they were exactly that; side characters that are not of importance to show and develope all the time.
I think you might just be too inexperienced with how writing and consuming said writing works for these. Not everything is a longwind that takes 1000 chapters to gradually show progress. The point of the comic was, from the get go, that they are pressed for time due to a world threat. Mastering skills as quickly as possible to beat the bad guy was literlally the whole plot. XD

And you seem to have a phD in yappology ig XD

Kiddo, I literally only addressed the things you mentioned.
If you don't wanna hear explainations, that's a you-problem. Maybe don't get into conversations or discussions if you don't like reading in the first place. (●'◡'●)ﾉ

That would be a nice wrap up for the story! Even if there no big bad guy they're fighting in the movie, I'll take some slice of life dang it!