They used to not require email at all. Did that change?

Yeah they did that a while ago, I think they even block temp emails (unsuccessfully)

I haven't been able to post to reddit in years now, because I refuse to browse it without a VPN, and while it still lets me in, any account that I make immediately gets shadowbanned as soon as I make a post or a comment.

I can't tell if it's because their bot filter is just terribly implemented, or because they don't want me on their platform if I don't surrender my public IP address.

I'm pretty sure they just use a "how many different accounts under the same public IP" type of logic, because even if I create an account on a 4G network (no VPN) and post, this happens. Cellular networks often use double NAT (unique internal/carrier IP, shared public IP) to avoid allocating a public IP to each mobile device.

I've given up a long time ago. My only exposure to reddit now is when a search results page links me to a post. The most helpful stuff is usually from a decade ago or earlier.

nahh, next is age verification :)