Random encounters are how most fights work in tabletop RPGs too, right? The DM just goes "there's a monster in this room; everybody roll for initiative"? With the logic being that as soon as you can see it, it can see you too unless you're deliberately in stealth mode or something.
That's an incredibly reductive interpretation of the concept from pen and paper RPGs, but so is the JRPG implementation, which makes it accurate in that respect.
But no, pen and paper RPGs aren't designed or written that way, and to my knowledge never have been. In a JRPG, you're interacting with the world in 1:1 realtime or navigating a world map that's a representation of longer distance travel, and either way, you step on an explosive pixel and have a fight scene come at you like a porn popup ad.
In a pen and paper RPG, especially D&D and the games closest to it, you can have a combat encounter randomly happen during a long travel, which is mechanically similar to the overworld of JRPGs but narratively happens after you've made your travel decisions and cut away from the party, so you're cutting back either to a rest scene or a fight. Compare the colony game Rimworld, which has exactly these kinds of travel encounters - in context they make sense.
Dungeon enemy encounters usually aren't randomized in pen and paper games, which makes them a lot more like setpiece enemies than random encounters. Whether you see them before they see you has more to do with how you're scouting around. There's a reason MMOs call dungeons "runs" and pen and paper games call them "crawls".
