How to stop spam signups

My site has gotten bombarded with spam signups for a while, is there any way to block these annoying af spammers? I tried Recaptcha, ‘verify activation link’ route but users are not getting the emails (which is another question on why they aren’t getting emails? I know ‘manually approve by admin’ exists but that seems like that would be a massive time suck.

Are there spam signup Plugins you rec’m? The more lightweight the better. I tried Ban Hammer and another anti-spam plugin, but the first one didn’t do crap and the 2nd one I think gave me a DDOS, ’cause it happened right after. If there is an existing or planned Ultimate Member already integrated solution, even better.

Thanks for any help