My son, was in his 3's, and was still in his crib. He LOVED his crib.
He continued to sleep and nap in his crib... until one day, HE told me he wanted to not sleep in there anymore.
So then, I put him on a floor mattress.
He has done fine ever since.
It was his choice... and he expressed to me his thoughts.
We don't have bedtime battles.
Next, before my son sleeps, he likes to twiddle around with or play with a toy car or whatever. So that is a PART of his/our routine. I let him. It helps to wind him down. Its no biggie and its okay.
My son knows that. Then, after a few minutes I tell him to put away and he does then he goes to sleep.
At this age.... a parent STILL needs to "cue" a child... they can't tell time yet nor even know that it is 11:00pm or that 1 hour has passed.
AND they simply cannot self-regulate on their own. You need to cue him and help him. He is only 3.
all the best,
Susan