It’s not that the other Zelda games suck. It’s that from the very beginning the bar was set high.
Legend of Zelda - groundbreaking in its time. Many would consider this better than Mario, and at the least the other main Nintendo series.
Adventure of Link was a lot of fun for RPG fans, but by that point in time it wasn’t altogether so far above other existing side scrolling adventures (Faxanadu, Castlevania) or RPGS (Particularly Dragon Warrior games). It held a special place for me at the time, and I still play it to this day.
Link to the Past was the Zelda game that passed the bar. In various publications it remained the #1 16-bit game for years.
Ocarina of Time passed the bar
Majora’s Mask, while creative in many ways that would make it more interesting to people like me, didn’t exactly blow away people like Ocarina of Time, Link to the Past, or the original Zelda.
All the Zelda games that came out in the meantime had interesting elements, but not one of them blew people away. They weren’t hitting that bar that the previously mentioned trip of games were. The handheld games weren’t even trying... At least until Link Between Worlds where they said “see this non-linear approach to a classic? This is what we can do!” and people loved it.
Breath of the Wild is the first game since Ocarina of Time that is a clear argument for “this is the best game you can play right now” and it blew people away - myself included. So yeah, it may sound like I bash previous Zelda games, but I still liked the series quite a bit. Part of the issue with past games is the pacing was getting longer and longer - and they felt very linear, with the overworld being obstacle courses between dungeons.
Breath of the Wild made Legend of Zelda LIVE in the world, the first time the game has felt like that since perhaps the SNES. Despite being a FAR larger world, the pacing issues of dungeons was fixed - and while thematically the temples may not be as interesting; they overall felt a lot better to play through because they weren’t an oppressive 250 minute trek through puzzles and hide-n-seek games (little keys hidden in obscure locations in very large rooms or series of rooms). The pacing was brought back down to the level of Link to the Past. So aside from the experience being quite mind blowing, it was also a lot more fun than Zelda had been in 25 years.
Emergent gameplay is also a factor, a lot of people like to get very inventive with the game and it’s physics. I think this is a big part of the appeal and what draws others in. Not only is it non-linear, but there’s a lot of ways to do stuff, not just the same thing every time like all previous Zelda games. People have different experiences, and so when people talk to each other about the game, they’re exchanging unique information - you could talk to 25 different people and get 25 different stories about the same area of Hyrule.
There’s a lot of internal storytelling to - people on youtube trying to be the best snowboarder, or the funniest jackass, or the most prolific and prosperous hunter-gatherer; and they teach people their methods to success; some like to be inventors, and they show what kind of flying machines they have created and give tutorials on how you can do it too. Trying to herd guardians... There’s A LOT of emergent gameplay and storytelling. It’s unlike most games in that way: Dwarf Fortress and Minecraft are the only two I can really think of, and Zelda DESTROYS them in production values (not that the fans of DF and Minecraft give an ass about production values though - DF players often say that the storytelling is so good that better visuals and UI are really a minor detail).
But yeah, Breath of the Wild topped the bar - that doesn’t mean that other Zelda games suck, only that they aren’t in that club of Legend of Zelda, Link to the Past, Ocarina of Time, and Breath of the Wild - each of which in their time were considered by many to be the very best game you could play and an undeniably awesome experience.
I describe myself as a little dose of toxic masculinity.
