In my recent experience, local meetups and groups are unexpectedly more prone to self promotion and low effort spamming.

Local groups have a problem where members admit their friends or pressure others into inviting their friends who are not a net positive, but it feels too impolite to refuse or to kick someone out. Meeting someone in person also develops a sense of a social bond that makes it harder to downvote or flag their posts.

Local groups have always been a haven for affinity fraud, too. Running a scam is easier when you can smile, be charismatic, and pretend to be a personal friend before springing your ask on to your victims.