HP doesn't represent actual hits, right? (It's an age old discussion). The "hit" that drops you to 0 hp is the first actual hit, when it comes to Zat'Nik'Tel.Zat'Nik'Tel weapons for instance - they ALWAYS drop you in the series no matter who you are and kill subsequently (if human and not serioulsy augmented in a way the main characters weren't) so they are an IWIN button once you have a big attack bonus and multiple attacks...
Well, the baseline for 5e is that low level enemies remains relevant at higher lvls due to bounded accuracy.The predominant enemy soldiers for most of the series were the Jaffa - so are they going to level with the PCs or become an irrelevant speed bump when encountered after about 5th level?
There are plenty of 5e based modern/sci fi games that handle this, plus many more d20-derived as well. It's solvable.If there is a multiple attack progression for martial types, how do you narrate your FN P90 on full auto magically getting more attacks in if the trigger is pressed by one person over another?
The weapons in Starfinder have to level - which is an awfully counter-intuitive mechanic and not one I have heard is well loved. But then there is ultra-tech everywhere in that so at least it can be narrated without cringing - in sharp contract to Stargate where the main characters of the series continue to use the assault rifle for most of the many series, so that isn't an option either.