The single biggest detraction from modern, for me, is that the limited edition cards make it impossible to collect your favorite player. A few years ago I tried to 'collect the rainbow' of 2018 Leaf Originals Metal cards of Errol Spence, Jr. (a boxer I really liked and thought had HOF potential).
Problem is, I could never get the last few cards, the 1/1, the /2, or the /3. It is just not 'normal' to be unable to finish a set or run. I got frustrated and simply quit.
I will be airing a ton more grievances with modern in my blog.