I forgot that experience only gives Ashley new abilities, not any tangible growth
Still, it's obvious that we have different ideas of what an RPG is, so I won't try to change your mind. I'm just happy I got an elaboration!
Returners Represent!
And Zelda as well as tons of other games also have that - that it does only happen through equipment automatically contradicts the state of official RPGs as RPGs. Whether it is 1 or 2 stats less or not. People are trying to define an RPG so heavily focused on stats and stuff and cases that suddenly other RPGs also are no longer part of the pattern.
In truth the argument is kind of pointless because people have their set definition of what is and is not an RPG, and nobody's going to convince them to change their definitions.
It's also why I usually try to stay out of "is Zelda an RPG" discussions, though I also usually fail at this
If we get to make up our own definitions, instead of using the ones defined by the people who define what the genres are, then I'm going to argue that Contra is an RPG. Because smurf you.
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There are a lot of RPG's that don't use Experience systems, but their goal is a clearly-defined progression, perhaps through equipment, skill points, etc. I'd argue Vagrant Story rather cleverly uses these systems and is an RPG consequently.
In most entries barring II and BotW, Zelda isn't an RPG because new gameplay elements are usually handed to you more or less as the plot allows it, Link can choose to forego his skill in weaponry to be better at say, diplomacy? Stealth? Not really. There's elements there, but there's no way to really translate a majority of Zelda's elements to a tabletop role-playing game. Dragon Quest and Final Fantasy were inspired by Ultima, The Bard's Tale, and Wizardry and all five of these series were love letters to D&D, so even though a lot of their mechanics might not be as transparent as in D&D, they're built on a foundation on simulated dice rolls, skill checks, initiatives, etc.
EDIT: I would not be opposed to someone calling Overwatch an Action-RPG for this reason, every ability and weapon has clearly defined damage outputs that can interact with other abilities and criteria and knowing how they interact is not unlike a highly streamlined set of dice rolls and essential to getting good at the game.
Breath of the Wild is Zelda's already existing RPG gameplay The Blunt Edition. Everything you could qualify BotW an RPG for already exists in one form or the other in other Zeldas. The Stamina bar as in Skyward Sword, the different and also improved gear, et cetera, et cetera.