Nope, there isn't anything like a lifetime VPN and if you find one it's probably a scam just like "free" ones where you are obviously the product. Mullvad is also not very expensive (5$/month) and extremely secure (no email or any identifiers, payment with Monero, sign up over Tor, wireguard tunnels). VPNs are services that generate costs from your usage unlike software that you develop once and then sell to make up the costs. Also keep in mind that VPNs only protect your IP from the other services you are accessing on the clearnet: they aren't a one size fits it all solution. Consider other OPSEC measures depending on your threat level.

you don't pay for lifetime packages for services that cost the provider money on a month to month basis like a VPN, any service that does this is a huge red flag.

the service will probably go bankrupt before you get your money's worth out of it