A lot of Republicans claim to be pro-choice, enough for a majority in each house. Also, the Democrats had a majority in both houses when SCOTUS handed down the Dobbs decision. They could have easily changed it then.
The filibuster rule can be changed with a simple majority. That's how they changed it when they first confirmed a justice with fewer than 60 votes.
The reason why they don't want to make abortion legal and settle the issue is because it brings in lots of campaign $$$ and rallies the base on both sides.