Hopefully your dismay is directed towards your host. After all, it's a fairly innocuous set of functions, related to mathematical operations (which we actually use in the context of encryption, therefore security) so it's a fairly pointless thing to be stubborn over.
Right. So I at least will post something that actually helps, I dread of getting another host. That's just odd and ridiculous to ask people getting another provider.
Go to cpanel
Search for php selection
Make sure you are using up-to-date php version
And in list below select gmp