rematch? ok to say no?

It's up to you. If you wish to accept the rematch, fine. If you want to move on to another opponent, all good. There is nothing rude in declining a rematch.

very ok
you dont owe your opponent a rematch
you clicked "play game" to play once
not on and on
personally i never request rematches but if i get them then i will accept
chess.com should really create a subpool where whoever you end up paired with, you play them in a best of x (x can be changed)
so all the people entering for a rematch sequence can stop being surprised that their opponent refuses a rematch when they never signed up for one (the opponent) and instead go here; where they ARE owed a rematch

That's why I usually play in tournament events for blitz/speed chess. People play terribly and think if they only get another shot at it, they'll get a different result. You owe these people nothing.

To be fair sometimes English isn't someone's first language and they mistake the rematch button for the new game button.

Whenever I play bullet and (I lose all the time) and the person wants a rematch, I never say yes, 'cause I don't want to keep losing and boost their elo.

It's rude if it's accompanied by something like "I don't wanna' waste my time playing a patzer like you" or "Go jump in a lake" or "Bite me!" Otherwise, it's perfectly alright.

It's rude if it's accompanied by something like "I don't wanna' waste my time playing a patzer like you" or "Go jump in a lake" or "Bite me!" Otherwise, it's perfectly alright.
imma start doing this thanks for the advice

"Whenever I'm losing, I must have rematches!",
the Patzer repeatedly, heatedly cried.
He continued to lose even more games, in batches,
and rematched and rematched until he died.