Go with something mil-spec - Colt 6920, LMT Defender, Daniel Defense, LaRue, or an upper / lower combo from BraveCompany USA. These guns will stand up to hard use.
Avoid the hobbiest guns - Bushmaster, Rock River, DPMS, etc.
LMT, Daniel and Larue are considered “boutique” ARs.
Excellent quality, but far more than the first-time AR user needs. A LOT of the features on those aren’t “mil-spec” because the spec calls for something different.
Bushy and RR are far from “hobbyist” (government and LE contracts) and and avoiding them would be a huge mistake, because they offer some of the best bang/buck value.
Colt is good, but their fire control pins is the kicker. That puts them out of mil-spec on that alone. Otherwise, Colt would be near the top if it weren’t for the $300 increase for name alone. I have a 6721, but a similar AR can be had for $400 less.
Bushmaster is the #1 manufacturer of ARs for civilian use and has been so for DECADES. Better customer service than the third-tier manufacturers, to be sure. Also a metric ton more options.
Just so you know, a lot of those “hobbyist guns” are made by LMT using the same billets as the others. CNC machining ended a lot of the differences in rollmarks. I have an Olympic...upper and lower match up better than a Rock River, and LMT did the work. Finishes are where a lot of differences can occur.