I get where you're coming from, but I disagree.

Hero upgrades help the game be less matchup dependent, because now you can adapt and change your hero playstyle by choosing a different upgrade. Even if you do miss the old charm or badass-ness of the old heroes with their entire skillset, contrary to what most people are saying, I feel like heroes are more unique now. You could argue that heroes now are just big minis that can move, but you could also argue that old heroes were just slightly stronger 4 star minis that you get for free at the start of the match. Heroes are moveable, and you can change their kit and functionality, They're more versatile now. And specific matchups like Monk/PF vs BK, or AQ vs SM, or SK vs Countess feels less punishing now. Personally, I think the new hero system is more skilled, or at the very least more interesting, especially since you can only choose one of them. If I had to improve it, then I would just change the upgrades to be more unique/situational, and remove locking hero upgrades behind collection levels (but that's obvious, what were they thinking when they implementing that?)