The only thing you'll objectively lose is quick settings. Every option is still there, it's just under different menus. Sometimes it's difficult for me to find things because I've used the other way for forever, but I like being able to use Bixby to change settings so I leave it that way.
I passionately enjoy using new tech! Occasionally, some actions are faster & easier to do in the manner I've done them for years It's like I love change but not all changes are super...