It's tilting to navigate the +10-12 bracket on alts.
I'm an above-average-ish player that does one M+ per week. On my new main (which is currently 385 ilvl, 2200 pvp, 8/8M Uldir, and <500 io score). Pugging goes like this: I will get silently declined for low score. Once accepted, various party members will threaten to leave the group unless I am replaced because my score is too low. Once inside of a key, players think they are God's gift to mankind for "carrying" me. The dungeon itself is a terrible experience. If i point out another player's mistake (i.e. alerting the tank someone facepulled so I dont get healer agro), then I will be met with some toxic jerk telling me to shut up and mind my own business. (I shouldn't point out mistakes, I'm being score-carried.) Oh, and If I make a mistake, I've now lived up to my low scoring expectations, inviting everyone to trash talk me. My bad dudes
If at any point someone quits, the process starts over again.
But I'm one of the fortunate ones. This experience is only a temporary inconvenience. I can weasel into groups by linking a plethora of achievements showing I'm a decent-enough player (Every raid CE since highmaul, realm first WoD CMs, realm first +15 legion keymaster, 2200 pvp current season, rank1 prog parses, etc). Alternatively, I just run keys with friends & guildies, which also raises my IO. Eventually, my alts get a score that is deemed "Acceptable" & groups which were previously inaccessible now can't wait to invite me (funny how that works). But for new players, I worry that this experience is not so temporary. They don't have a backlog of achievements to weasel into groups, or as many friends/guildies willing to run with them. I worry that it could be hurting the game by shutting people out when it's not necessary (esp. in <= +10s).
Raider.io is great cause it gives people another avenue to enjoy the game, but like everything else, the playerbase def takes it too far