I haven't run a forum since about 2012, but from experience I always preferred running off dedicated or shared hosts VS your own hardware. With the amount of bots and bullshit out there I'd rather the onus be on the host to ensure my site is up and running.

I constantly ran into having bots take over and flood each board with ads for p*rn sites, dating sites, fat loss pills, you name it.
Getting users was very hard as well - with most users these days preferring mobile access and uniformity, Discord is always going to win over old school forums, especially with the younger generation.