Yep, Framework (as far as I remember) intends to even create a public marketplace for people to sell custom-made addon cards. They have the dimensions on their github and make it pretty easy.
I personally doubt chess will fade. As far as I can tell, the enjoyment of high-level chess is less to do with reaching objective perfection, rather it's more the "thrill" of seeing a _human_ who has poured their life into the pursuit of improving their game. It doesn't really matter that a computer can beat them, we care about them because people like seeing other people's talents.
And on a casual level, nothing changes if the best in the world is a human or computer, so the casual player isn't particularly affected.
While the client-side has input validation, it appears that the server-side does not, as I can edit the request body freely and it'll return accordingly.
It's interesting to see how the model fails at extreme values. I can see why they chose the cutoffs they did!
FWIW, as a younger person, I have started to see friends (and myself) shift away from influencer culture as it becomes apparent it's unhealthy. When you see so many influencers quit due to mental health, it starts to add up. My perspective is likely skewed by the social groups I tend towards, but the cycle of influencer culture is so short-lived a lot of us do start to catch on.