20 years for vinyl tile is awesome! Congrats!

I would pull all the old floor and use cement board and ceramic tile.

But honestly isnt it time to look at the plumbing? How old is your
home? Drains plastic or metal?

You might be better off doing a complete bathroom redo. Since you home
is getting older

Any plans on selling someday?

If so do a job that will appeal to others!

Things like GFCI outlets, exhaust fan, additional heat, floor drain so
NEXT toilet overflow just goes down the sewer

Some put in a shower that has no step over, that way shower drain
drains entire bathroom in flood situation.

just some points to ponder