Not upgrading can sometimes be a choice, at least as long as the OS receives security updates, sure.Why upgrade?
Better is the enemy of well
But finding a solution is still important. For instance, next year I'll buy a new computer and hand this one down to someone in my family. The new one will run Catalina, with no downgrade possible. So I can delay upgrading for a few months, but it won't make the problem go away.