Did you notice the quote marks around adequately? We managed to hobble along but it was obviously not going great. "It wasn't catastrophic" isn't my goal. I want stuff to go really well, not just about enough to not go out of business/not be in violation of contractual obligations (with a lot of slack getting picked up by their better performing peers).

Again it depends if you have an alternative, in my experience I always had it was just sometimes costly/inopportune/a pain in the ass in the short term to find someone better. Long term it was always better (I never regretted firing someone too quickly but often regretted firing someone too late).

I was also always worried about team morale but every time a low performer was fired it actually improved morale.