Making videos is hard. Making excellent videos is extremely hard. It's easy to go online and say something good sucks, it's harder to do it.

Maybe you need to reframe your question. Maybe you need to ask why satisfactory ones are incredible? Videos are about marketing and to bring players in. Factorio does really well from word of mouth. Do they need excellent videos when nerds online are saying "the factory must grow". If you ask me, it's more effective marketing and much cheaper.

Do you need a perfect trailer for every game you pick up?

Satisfactory has a 3D element that lends itself well to trailers; FPV is always going to be more engaging than isometric; Factorio doesn't even have cut scenes to lean on (thank the gods!).

Honestly, the Satisfactory previews look fantastic, but paradoxically make me not want to play the game as much. It's because of the type of game; these are resource management games, with a little conflict, and that's what I'm looking for. If I wanted conflict with a little resource management, I'd be looking at a tower defense game. The Satisfactory previews look like No Man's Sky, on steroids, and it looks too busy.

That's just me, but my point is that I think the Factorio previews do exactly what they should: appeal to the type of people who want to play an isometric resource management game.

Those videos are just previews from the FFFs. My guess is they'll make a real trailer showing all the new features, similar to the main game trailers when space age is released

Satisfactory trailers are a class of their own <3

But which trailers are you thinking of? I know of only two: The official 2020 Factorio trailer which I think shows a good mix of gameplay and "concept", and the Steam Store page snippet for Space Age showing some new things like the platform.