Colt’s quality started tanking before the M1991... where they did such fun things as replacing the grip panels with cheap (not terribly durable) plastic. They also replaced the trigger pad and mainspring housing with cheap, not terribly sturdy nylon pieces. The finish on their AR-15s has also gone way downhill - the military (read: cheaply made) issue contract ones FN makes now have better finishes than the Colt Blue Labels of late.
Colt lost the contracts to FN (Colt no longer produces the military’s M4 or M16 at all) not because FN’s bids were cheaper but because the Army finally refused to put up with the sorry lame excuses Colt kept giving out for the low quality crap the Army was seeing. And Colt’s backup plan, use bought Senators and Representatives to block any change, didn’t work either.
I shoot with guys who speak of the quality (or lack of it) they remember in the 1970’s Colts. Apparently Colt didn’t learn anything from that. Never had a Colt and probably never will.