I couldn’t even choose honestly. Mauga is just obnoxious to have in any game, whether on your own team when you are support, or the enemy team. He is so loud and his damage is so constant and you spend so much time on-fire. Without a support picking Ana (or if she is banned) he can be a nightmare to deal with.
Hazard is also horrible to play into. His block is up way too often (just like DVa matrix) and doing damage while blocking and getting kills is just BS of the highest level. Terrible hero design.
And then Freja. I think others have said enough about her. Giving her burst damage with up to 3 shots of it back-to-back and flying high mobility, with no drop-off, is just insane. And, like Mauga, it just feels like her damage is constant with no break, especially for the tank.
Sojourn, like freja, is obnoxious because she has mobility, burst damage and what feels like constant damage output without break.
What most of the problematic new heroes have in common is too much damage which is available too much of the time and generally way too much in their kits (mobility + burst + high damage availability + 1 more ability).
Ram is ok now that they fixed the armour stacking bug, queen is a fun design (although currently OP and needing a sustain nerf), kiri is a fun design too and fun to play with and against and juno and wuyang (OP) are also fun, good designs.
They need to tone down the damage on new heroes. Stacking these heroes is just not fun to play against with constant and very high damage. It feels suffocating as you can’t move without getting hit by high damage.