What will happen if I let my 3yo dictate bedtime?

You guys I am so fried on the hour+ long negotiations and meltdowns that accompany bedtime every night right now.

Tell me if this is a really dumb idea? What will happen if we just shrug and are like, ok bud, you do you, you’re the boss, let us know when you’re ready and feeling sleepy? Am I delusional in thinking maybe this will make things more peaceful and he’ll just get all cute and sleepy and willingly wander to bed at some late (but not insane) hour like 9-10pm?

For reference we start the routine at 7, in bed 7:30/7:45, and usually can finally escape his room at 8:30- after sitting silently in a chair for an hour and periodically shushing him or negotiating various asks / excuses to get out of bed. If we leave before he’s sufficiently calm he throws things at the door and wakes up baby bro. Pushing bedtime back does nothing- it still takes an hour of us sitting in the chair. I don’t want to tonight 😩

Have you guys ever tried the “f it” approach, and let them do whatever? What happened? Please stop us from doing something stupid if this is stupid- thanks!