This was kinda my point (if more kindly,) that random encounters started off as a way to create the illusion of huge and intriguing worlds on consoles that could only support linear games that could be beaten in a half an hour. I think FF games were ambitious in that they had grand stories to tell, arguable unlike any seen before them, but limited capability to tell them, so they became elevator pitches wherein the person selling their idea found a way to stop the elevator every few inches to buy more time. We've long since reached the point where that's necessary, but it became such a defining part of the JRPG identity, they kinda went "if it ain't broke, don't fix it" for the next 30 years.It is much easier to make encounters happen every few steps than it is to create and animate creatures on the dungeon/world map for players to run into. Especially if one pairs it with turned based combat. Having visible and avoidable battles is not only an evolution of random encounters but objectively superior in terms of both immersion and player satisfaction. However random encounters still exist even now simply because they take less effort and testing to do.
Conversely, in the first Zelda, its story progresses through completion of 9 dungeons that can each be completed in a couple minutes, but they and the tools required to beat them are meticulously spread out across [arguably] vast expanses of emptiness and scant few enemies. But it's story is pretty flat, so it functions as an elevator pitch wherein the elevator has stopped unexpectedly, and the person selling their idea didn't come prepared to fill that much idle time, so they start effectively "answering questions with questions" to engage the audience.