These days many services ask for a phone number for 2FA just to sign up, it'd be great to have a tool that gave you multiple numbers on demand so you don't have to give out your phone number.
I've been considering just buying a few prepaid SIM cards just for services like this. I'd love some throwaway phone number/ SMS-forwarding services, but most get blacklisted within a few months because spammers immediately jump all over them.