There are a couple schools of thought on this. Just as I believe that a “loose” pistol isn’t necessarily inaccurate, I don’t believe a tight pistol is necessarily unreliable.
I own a couple of Les Baer pistols that are on the tight side. My 5” gun has passed the 9K mark and is still tight, no rattles and the slide feels like its glass on glass. Whereas for a comparison, my Gold Cup started out sort of tight and actually loosened up quite a bit as I shot it. The Baer still feels the same, just a lot smoother.
I’ve fired both it and my Stinger for 300-500 rounds at a session of 200 LSWC reloads and not had a single issue. Sometimes this is at a “slide too hot to hold” pace, and some of my reloads aren't the cleanest stuff going. Both of my Baer’s have digested everything I’ve run through them, and I consider them reliable.
Chuck