Honestly, in this day and age I consider VPN a basic internet hygiene. There are many many reasons to not trust your ISP and the wire between your home and ISP. You have moderation here, why do you even need to block VPN? I registered this account from VPN, but I somehow cannot comment from VPN? Doesn’t make much sense. I’m using paid Proton VPN servers, and btw I’ve seen Proton having a dedicated community here on this platform.
I agree with preventing your ISP from being able to see your traffic, but not necessarily on the mitm attacks. In either case, a mitm needs to be positioned properly.
As far as the ISP seeing your DNS traffic, there are ways to derive your real IP based on DNS queries. DNS leaks are a thing. It’s not necessarily true that 100% of your traffic is encrypted.