Yes, they changed some heroes to the point they literally are not the same hero anymore/plays a lot different and their personality is erased. Krul, BF, etc…
Also there are heroes that are for rework as the game evolved - 5vs5 and lets not forget a lot of new heroes - so 3vs3 is also a lot different. Those heroes are just not cut it in the current game state and while in the past their kit was OK, nowdays it’s not.
As for the balance debate, games should be balanced toward the high tier - learners plays the game different (don’t know not only how to counter strong pick, but also don’t know how to use it). Good player in the wrong MM spot or smurfing will stomp over the learning players with anything. As I learned how to counter SAW/krul/whatever hero in the past @ 3vs3 and when he was strong - now they can learn too if the balance is right for the high tier. Ofc as I said, some heroes are for rework nowdays - saw, petal, etc.
You can’t add tons of heroes with supa dupa skills and expect someone like petal/saw to do good without being broken as pure stats… and obv some heroes are not fun to play and suitable for 5vs5 even if broken, their kits are just boring compared to the new ones (hi ringo). So many transition errors… what about lance? Hero clearly designed for tons of walls and bottlenecks in 3vs3 map + only 2 dmg sources that made him really tanky and easy to face the enemy for dmg reduction (esp as in 5vs5 all fights moves so fast). Also what about balancing over the new boots? Everyone moves faster - skill shots are harder, ESPECIALLY with the bad lag the game have nowdays! Some skills like lance A are roflmao easy to dodge without even trying with t2 boots… even t1 boots is = easy avoid for any t7 real skill tier.
Not to be negative, but the balance was better with @nivmet… yeah, 5vs5 broke a lot of things, but he did a lot to try to workaround the heroes designed for 3vs3 and halcyon map. The meta direction is something I think he would balance better, but here we are… changes without really balancing some aspects around them. Something simple as speed boost is really affecting heroes. They buffed it how many times? The default speed, now boots… and how they compensated the time you need to land lance A? THEY DIDN’T. Just lower hit recovery if you miss - great, but the point of the skill is to land it.
Combine that with the big empty spaces where you can’t stun anyone with B, then the buffed speed that makes easy to go around lance = one would see why he is even worse than 5vs5 release (even if they pumped his stats). Lance was stun and protector king… right now he is just tanky and thats all. I go with lance, but really - this is valid for a lot of heroes and balance changes.