You can still have sci-fi in the flavour you described and have it labelled Sci-fi, but fantasy is generally applied to settings on the ground that use pre-modern age technology or magic.
Although, some fantasy settings can get this weird mix of modern and ye olde that I don't really like the look of. Usually happens when people make a lot of anachronisms.
I personally also hate rule-of-cool stuff like ridiculous armour and oversized weapons.
tldr I'm boring