>>39822332There have always been blocked paths, yes. There are two types of blocks. There are
>Story flag progression blocks>Inadvertent blocks due to game designThe old man blocking you is a story flag block. He won't move until you do the appropriate story event.
HM obstacles, Snorlax, the thirsty guards, badge gates, etc. are blocks that arise out of the way the game was designed and are solved with items, not story flags. If you hacked in the Poké Flute before saving Mr. Fuji, you could use it on either Snorlax. There's no message like "The flute rang hollow..." to stop you until you get the appropriate story flags. Same with HMs, though you need two items set (badge and HM) to get past those spots. Hack in all badges without touching any story flags and you can go up through the Pokémon League Reception Gate. Hack in a drink and you can give it to the guard as soon as you try to leave Cerulean City (and this one is actually officially possible because of Stadium 2 letting you transfer items between games).
The key difference between these two blocks is that one is arbitrary to the player and included by the developer to artificially gate them in lieu of story progression, while the other is something the player feels like they can solve if they could just obtain the item. You aren't given Surf, or really any HMs in Gen I, through story events. You see water and you think "If only I had Surf to get across it", so you go and find Surf of your own volition. You aren't being directly told what to do by the games and being blocked until you do it. While there is an overall path that you do follow, most of Gen I's obstacles being tied to owning an item or two obtained by the player's own will does make the game a bit more open in what you want to do first and the order of Gyms, and it also gives you the feeling that your adventure is being self-propelled.
In SM, nearly every single block in the game is an arbitrary story flag block, and they're everywhere.