so far all the good VPN provides are accepting bitcoin payments, in fact they have been doing this for a very long time, probably ever since bitcoin became a thing and gained some popularity back in 2010ish. there is a good website called https://thatoneprivacysite.net/ which was created by someone on reddit at first with just a google doc thing and then with a lot of additional information which you can visit to see the list of all of them with their methods of payments. you can see the good ones there are already accepting bitcoin.