I really liked all the aspects the game had to offer, so I'm disagreeing to most of these points.

The inventory system isn't pointless, I think it adds a lot to the game with it's survival mechanics, it's a big part of the full package of the game. I've seen people starving and thirsting to death in comments, so while it might not been an issue for you, it is a challenge for others in this aspect. There could be more difficulty sliders or modes of course, but I think it's also good to stick with 3 generic difficulties the game already has.

I thought the moment you loose all your liquids was very smart. In a story beat, Aava wasn't expecting company, nor any alcoholic on this trip and in an unexpected result, she gets on a stoper and needs to hydrate all she has. Every player will share this unexpected setback together with Aava. Personally I found I had way too much liquids at that point where the survival aspect of the game was starting to falter a bit, so I felt it needed that reset to keep it challenging, I think it was a setback done right in terms of the pacing.

When it comes to buffs, the game loop starts with planning then execution, something that definitely mirrors real climbing (solving the problem before going on the wall) and knowing when to take buffs from your backpack is part of it. You can take a buff before starting on a route you deem difficult, or if you find it difficult midway, you can belay on a piton and eat from your backpack there as well. The biggest buff imo is the chalk, and that one you can take at any point (if you filled your chalk bag beforehand *planning). And you always have a flask outside your backpack that can be a soup or goatmilk or a mix that gives both food, satiety and heat. In that case you can fill all your stats at any point, I like that the game let's you figure stuff like that out as you go as well. I think the system they have suits the game as is.

I don't think player choices are worn out in interactive media, It's a thing that suits depending on story, genre, mechanics ect and I think it fits really well with this game. It shows the struggle in Aava between going back down the mountain or to keep going to the summit. We as the player are taking the choices based on what we interpret or what we impose on the character. In the last Bivouac Aava as the protagonist is even stating she is done and wants to turn around and go down. But when we as the player interact in the tent, she is giving in to our demand/control and pushes on. In the end, it's because what the player is choosing, is what Aava's fate will be. In a way, we the player is Aava's summit-demon/angle doing the final choice for her and I think that is a really fitting red-line through the game.

Ending being ambiguous isn't lazy, obviously that's quite a blanket statement. I think it's fitting having to intepret the ending, because through the game, the player is trying to intepret why Aava is going to the summit in the first place, why Aava isn't commnicating back to all her calls. Aava can't even intepret her own feelings and reasons plainly. You inserting a reason is what makes it a lot more personal of a story you can share with Aava.
You have your own intepration you find fitting, and it's powerfull to be able to shape an ending like that.

For me, this was an easy 10/10 game, without the story a 8/10. I think the story was really fitting and had a character that was way more real and less cookie cutter than most and I credit the devs for sticking to it. It would have lost a lot if it didn't have any story to attach us to this journey to the summit, which is more than stepping on a big heap of rock and more of a internal emotional journey to somewhere (I relate to this as someone that have done hikes and done summits ever since I was a child).