They might be very different games (they are)
And that, to me, is end of discussion (for the purposes of the thread title) right there.
I fully agree that, with the exception of planetary landings, there hasn't been a single update to ED that's been an imropvement for me, and there have been many that have actually been detrimental. The Lifetime Expansion Pass was a monumental waste of money and from my point of view I effectively paid £120 for Horiizons.
But:
I'm still playing the game I bought on Day One and was delighted with. Sure, I've all but given up hope on the game getting any better than it is, and I've spent way too much money on it, but I still play every day. I've stopped ploughing money into vanity store items as I recognise that I'm not getting value any more but I still play, and most days I still enjoy.
I purchased Nomanski on launch day and the first thing that sturck me was that is was clearly aimed at consoles (I'm guessing PS4 but I don't know about that stuff). I failed completely to work out how you're supposed to remap the controls. Clicking on stuff seemed to have no effect in the menus. So I played for about half an hour with the default WASD and then requested a refund. I'm not saying I gave the game a fair chance but it was enough to demnonstrate that this wasn't for me. That trailer just showed me more of the same cartoony graphics and poorly animated third-person view that I personally am not interested in. It just looked like the same game with lots more stuff.
I'll just keep playing the same game I enjoy and hope we get more stuff eventually, and silently regret spending quite as much as I did, while still enjoying what we have.
TL;DR: stuff is nice, but the game itself wil basically remain the same. This applies to all games.
Usual disclaimer, this is just my view; yours may differ.