If you let your points build up without cashing them in, you were gambling and lost. Bad gambler.
International players did not have the option to exchange points for BTC. Although I heard a few select international favorites apparently had that option (possibly commiting fraud via VPN and false residence info), I certainly never did.
My only option was to exchange them for sportsbook cash, which I always did ASAP. It was my cardinal rule NOT to save up points because their value was always dependant on goodwill anyway.
They slowly removed all the books that still worked for me though, and around 2 years before the 'sale' I ended up stuck with no outs for the points.
I also won tons of points in various dailys etc. after all my outs vanished.