I, regrettably, am one of the nostalgia nerds who still thinks original gold-cartridge LoZ is my favorite of the series. Also regrettably, I haven't even played the SNES or N64 titles. So clearly I can't speak to any failures of MM and OoT.

I can speak to the current game w.r.t. other current open-world RPG titles.

It has all the game mechanic trappings of a Bethesda title (Morrowind, Oblivion, Skyrim, the Fallout series), but without the bugs that Bethesda is known for. There are endless side quests to run; you are not confined to essentially a single path through the game, no matter how many times you play. Yes, the main quest is there, and will be the same for all characters, but doing the main quest is truly an optional experience in the game. You can have hours of fun exploring the countryside and doing favors for the people you meet out there.

E.g. There's a food crafting system in which you use a cookpot or campfire to combine ingredients which have different effects.
E.g. There are different biomes, including a snowy biome which deals you cold damage over time. Changing your clothes or eating foods to cancel the cold debuff are a couple of options for dealing with that.
E.g. There are "magical" powers which Link discovers and uses which allow for the problems presented in the game to be solved in multiple ways.
E.g. The world is vast (it's described as bigger than Skyrim, but how to compare the size of fantasy worlds in different fantasy universes is beyond me). Seeing the distant mountain peeks and knowing they're not just a background, but an obstacle to cross with new vistas and adventures beyond it is perhaps not new to a Zelda title, but they've done it on a grand scale.

There's so much more to this game. These are just a couple of examples of where Nintendo has taken the best mechanics from other RPGs and woven them into a Link tale.