3ds max or Blender

You can always look through the infographics in the news section to see relevant data. For example the last infographic in 2020 was 14% for 3dsmax.

In the end while native format is helpful for the customer as long as there are additional formats they can be useful for a larger customer base, such as fbx, obj, etc. If you take the time to make your formats 'native' for both 3dsmax and blender then your offer can reach more customers, meaning they look 1:1 in both software (PBR is the key here obviously).

https://www.cgtrader.com/blog/one-millionth-3d-model-uploaded-to-cgtrader-infographic

In my opinion quality of the model have nothing to do with software itself , it is the skill and knowledge of the artist. It doesn't matter is it max , blender etc. "Best" model is about good topology, shape precision (if it's replica of something from real world for example) precisely done materials etc. As 3DCargo said , nowadays you can achieve 1:1 look thanks to PBR.

I´m pretty sure they have been made by experienced professionals that have the time, money, patience, and *mental panache* to finish "big" 3d projects. Hence, soft is unimportant, MONEY is important, assuming you are experienced and 3d is your second home.
If you have money, you don´t need to earn anything right now to pay your bills, and you can focus on just working into the dark with the well known mantra "it´s done when it´s done". Kapish?
All the best selling assets are most probably done by artists who are "baked" by investors or have a good financial standing. Without money, good luck with creating "best selling" contents!