The whole ban invasion rule never made much sense to me. It's completely unenforceable, there's absolutely no way with their platform for them to tell if a user is using a new account to evade a pre-existing ban, so why the hell are they going on about it?
It's enforced, believe me. Even with a VPN. I think they must use browser and app fingerprint, it isn't just IP.
In the end it really seemed like I had been flagged as an undesirable. I'd have what I thought were pretty reasonable discussions at night, and then wake up to another account permabanned. The last couple I didn't even get a link to the offending content, just a message about being in breach of their content policy in some undefined way.
If you're going through many extra steps to change your online fingerprint, then you're correct. But there are things they can use to match accounts together. Even a simple IP address combined with behavior from that address can be effective.
In my limited experience with ban evaders while modding on reddit (on a ~100k subscribers size sub), reddit's automatic systems do catch some ban evaders. We would sometimes ban a really angry person and later find multiple comments from different accounts in the filtered queue trying to continue their bickering.