Yeah, Ubuntu was great long ago. Nowadays its parent company is trying to push new standards (started with desktop environment, then with how to install apps) that are extremely shitty takes on open source solutions. They need to be more humble... Imho, Canonical is no better than Microsoft. It's like they want to be in that position, next to the 'great players' and just try so hard. Knowing one's place requires too much wisdom.
PS: I hoped all around Debian distros, my favorite is now MX Linux "ahs" version (:
iirc Mint removes a lot of Canonical's enshittification (i.e. snap) so... No. LMDE is more of an experiment for whenever 'cleaning' out Ubuntu turns to be much work or impossible, as a viable alternative. But right now, both Mint editions are acceptable and afaik the only difference is about using PPAs.
PS. I might be wrong, but this is what I learnt when I used those distros (around 2012-2014)