I have a few personal things hosted on IPv6-only just for giggles. A few years ago those things would almost never be reachable. Now I can reach them at most places. I at least have IPv6 on cellular connectivity all the time.

Before long, not supporting IPv6 will make your website more unreachable than not supporting IPv4. (Already the case in Asia ?)

Let's say that I am considering this too, have looked a bit into it, but I am not a network engineer, and haven't done it yet, so I am not sure how good that advice is ?

I guess this depends a LOT your ISP, and especially the router they gave you, how much IPv6-only friendly are they ?

Yes, you can buy your own router, but this come with even more complications and potentially negotiations with the ISP.