Similar reason for me. Although, as long as I could get a car without internet connectivity, I would even be fine with non-free software but even that is too much to ask nowadays. This also applies to gas or diesel powered cars though, so I will stick with my sedan from 2015 too, might even have the engine redone completely in a few years if there are no proper options by then.
I am not extremely familiar with nix and flakes but from my understanding, they create isolated environments like venv or containers, correct? Would that not mean having a separate wine install and especially separate Lutris install per Game? So no single Lutris that lists all games but a separate one for each, kindof defeats the purpose I think. I fail to see the benefit over just clicking it on the lutris website, so not sure if this would gain traction. Open for any suggestions and corrections though!