There are users who moved to Hive when the Steem chain was hacked in 2020.
There are also some who started posting on Steemit after they had started on Hive.
Almost no one did it the other way round. Those who did this were usually spotted by Hiveians.

By deciding to stick to Steemit for so many years and being heavily influenced in content creation for that platform, you automatically supported and promoted it.