Most people Pugging are just trying to get their weekly done so the Wowprogress M+ score is moot. Sure you can go look it up but chances are people with high enough scores arent pugging them. The only people pushing for +16 times are guild grps
I've pugged anything above 15 exclusively outside my guild and have basically all dungeons on 21 or higher. Lots of people pug it and with Discord it's fairly easy to coordinate.
I mean, sometimes there's 1 or 2 guildies in the group but that's about it.