I tried something like this for my office chair. It was fine as a seat, but it raised my overall position on the chair vs the backrest and i ended up throwing out my back from the resulting offset. So, mind the chair you intend to use it on.
My gaming chair, while comfortable, is woefully under cushioned. I actually bought the exact cushion labs product in the picture and have spent many a long day sitting on it gaming away without any complaints besides it occasionally shifts on the chair. One of these days, I'll upgrade to a better chair, but in the meantime, this was a quick, easy solution that has worked well for the last two years now.
That’s gonna fuck up your stroke bruh. If you want a seat cushion for a rowing machine a folded towel or a piece of an old yoga mat will do. You can buy more expensive rowing specific seat cushions but it’s lowk not worth it unless you’re spending a serious amount of time on the erg (and are still uncomfortable)