Cat's claws not fully retracting

My cats both needed their claws trimmed ever few weeks. Invariably, one claw would get super sharp and not have been pulled off yet on the scratching post so it needed a trim. Usually a dew claw. It was a good time to do them all. Saved them hanging up on things. It didn’t start happening until they got older, but I think it was less a matter of their varied health issues and more a factor of just not being as effective on the scratching post as their energy levels slowly diminished.