> They don’t really have a monopoly on local events or marketplace.

Yeah, I'd say from 2004 - 2015 was the heyday for me on local events for small bands, house shows, and punk/DIY venues. Eventually FB Events died out socially by not being able to send invites to mass groups of friends/previous attendees, and attrition, and so on... A real shame for non-major venue events and the DIY scene.

Marketplace is semi-useful still, quasi-better than craigslist, but keeps getting filled with a lot of cruft of drop-shippers and scammers.

I had almost forgotten about the 2004-2015 music scene on Facebook. For me things died down around 2011 when the police started using Facebook to identify and break up unlicensed events.