There aren't many independent forums left anymore. Reddit is still an option but eh, Reddit has killed so many forums already, and there's no telling what else they'll do to push revenue in the future.
Discord is a closed ecosystem that sells data to Tencent (and then lies about it).
Could always moved to Tom's. Ha! ha ha. Ha ha ha. Ahem.
Realistically-speaking, for anyone who is not chronically online and/or using the forum as a timewaster, the slowdowns are . . . survivable. I spend less than an hour/day on AT forums and can find ways to participate in the CPU forum threads that interest me in and around the slowdowns. For lifers that love lurking in OT constantly it may be more of a burden.