This can actually be a very effective way to turn someone's feelings around (and feelings are what matters), at individual scales. Ideally without letting on that you're a lockdown sceptic, put it to them that masks, distancing and lockdowns should continue forever because they protect against flu, which kills 10's of 1000's per year. And suggesting outrageous responses to other things as well, as you suggest. You can make them start arguing your side, in fact.

Similarly, if you tell someone that lockdown will kill many, and younger, people due to missed cancer diagnoses, they put their shields up and will dig in. Instead, propose that lockdowns are actually curing cancer. They ask why/how, you explain how cancer referrals and diagnoses are down by whatever % this year, so that's a great thing, surely. Then they will have to show they're smarter than you by explaining it's actually because people aren't getting seen and the cancers are going undiagnosed.

Gosh, you say. That's not so good.

Things like this do actually work quite well in a lot of situations. It's all about manipulating emotions and altering the perceived hierarchy in the conversation (let them defeat you by taking on your own point of view), etc etc.

Something that often creeps up using this analogy is that the consequences of the activities OP mentioned "aren't contagious."

We'd need a rejoinder to that. Of course, things like car crashes can and do affect other people, but it's not quite the same as the supposed exponential growth of infection trotted out justifying the exception to corona.

Maybe something about bush fires? A Grenfell analogy?

Thanks for your replys and ideas, I will start to try and shoehorn this into conversation's with true believers. 👍🏻