Is this normal? 1yo doxie needs constant supervision

My mini dachshund just turned 1 and he still needs constant supervision if he’s not in his playpen/crate. He will still chew on random things, have occasional accidents, and even worse, pick fights with my cat.

Is this normal? Did I do something wrong? I read and heard that it’s normal and needed to keep an eye on a puppy when they are young, but when do we phase out of it?

My dog also has endless energy, will refuse to sleep unless being forced to (crate), will tire out all other dogs (even the big breeds) and then still has all the energy to run around.

He has just been neutered 2 weeks ago and that also did not change his behavior. I feel he’s probably even more agitated these days because of the pent up energy that he saved while recovering from the surgery.

Any advice would be so appreciated!!! Thank you in advance 😭😭😭