The difference is that Mullvad doesn't enable any east/west connectivity at all. If somebody guesses a user's Mullvad 16 digit number, they can use Mullvad's services as that user. If somebody gets a SmokeVPN users's 16 digit number, they can connect to that user's other devices.
How would you take any action with an abuse report and no logs? You'd get a report or subpoena or similar that listed an egress IP and a timestamp and say "We need information on this user for this charge" or "You're ordered to halt this illegal traffic", and you'd not have any way to tie that out to a specific user retroactively. There are plenty of providers who take the stance that they don't log and thus effectively cannot prevent or restrict illegal or abusive activity. I'm just not understanding how you could claim to both be logless and restrict those things.