That rather depends on your usage pattern, I expect. Twitter has similar inconsistent reports, and I can confirm personally that I was suddenly asked for one as soon as I tried to post anything; I believe I also had something like that happen with Discord, but I don't remember as clearly.

Not that it's necessarily malicious in intent—requiring “extra verification” only on suspected misuse isn't entirely unreasonable, and that's awfully hard to distinguish from things like targeted privacy attacks—but it would be nice to establish this sort of thing as common knowledge, especially since I imagine the chaff of “huh? no they don't” is only to their benefit.

Every major discord server (if you are not just strictly in DM with friends or make your own with friends) requires phone verification with virtually no exceptions.

Using any form of datacentre IP or anonymiser requires phone verification randomly within a few minutes or hours of starting interaction [regardless of server].

You get a different error message and cannot use discord at all: https://i.imgur.com/T57xcff.png

I cannot confirm either of these claims. Although the former depends on the exact definition of "major", I guess.

And don't block VPNs either. At least not mine. Not sure where GP got this information.

I can nearly guarantee an account ban if you are on Firefox with uBlock + resistFingerprinting and use any popular VPN provider (Hetzner, OVH, etc).

It depends on the "server" owner.

I think the internal term is "guild".