all it does is give you the invisible condition, anything beyond that is your ‘wishful thinking’
That's basically what I said. If you compare the two, you see the difference is in execution, not effect.
Hide Action
Grants the Invisible Condition
Requires you start in 3/4 or greater cover and/or heavy concealment
Cannot be done while you are being observed
Needs a DC 15 stealth test
Lasts until you are found, make a noise, or attack
Can be found with a Perception test vs stealth roll
Invisibility Spell
Grants the Invisible Condition
Does not require you have cover or concealment
Can be done while you are being observed
Does not require any sort of test
Lasts until you attack, cast a spell, deal damage, lose concentration, or after 1 hour
Cannot be found using simple Perception (? I'm not sure how this is handled. The spell doesn't say, so it might be part of the Search action)
Requires a 2nd level Spell slot.
So while the hide action requires harder to meet criteria of not being seen to hide, the spell just hand-waves those conditions away for the same benefit. It's an illusion spell to boot, so it makes sense the in-game fiction is that you are using illusion to mask yourself in a way that couldn't be done via mundane stealth but notice I did NOT say translucent.