Played the beta, and yeah it did kinda feel like a step down.
The guns and enemy attacks all feel less impactful, I remember KF2 having a lot more punch to everything. The guns especially felt very weak, and there's a lot less options than before.
Classes are locked to a specific character skin instead of letting you pick, but that might've just been for the beta. (Edit: my bad, just saw that they are indeed changing this part for launch)
Also, for some reason, the enemy designs all look more similar to each other instead of more distinct, which doesn't help when trying to identify which enemies are which.
And, I saw a lot of stuff that pointed to negative mtx and monetization: battle pass, dailies/weeklies, tons of cosmetics, all the usual suspects.
All that being said, I still hope the delay lets the devs fix a lot of stuff, I really liked KF1 and 2, and there was stuff in the beta that I liked (loved the soundtrack, and the maps looked really cool). I don't think the beta had any issues that can't be fixed, so I'll wait and see.