They can make it impractical for most people by repeatedly banning VPNs by IP address. Users have to pay upfront to figure out if their chosen VPN even works, then it could still break later.

And some including mullvad already accept payment in crypto, there will always be some dodgy VPN company in some dodgy jurisdiction that will take your BTC in exchange for an account.

I don’t think that will stop them trying though

Like in Russia

    - drop wireguard / OpenVPN packets crossing the country border
    - analyze https traffic to detect traffic patterns not matching https fully and block such connections