He also pretty clearly doesn't expect to actually win Lord Mayoralty next year. He's using his candidacy as a way to help prop up the local ward campaigns of other candidates, as well as to bring attention to the issues that he believes in. This much was, IMO, obvious just by paying attention to the polling numbers and history, but he actually came out and said it explicitly a while ago too.

I wouldn't be surprised if he runs again in 2028 for the same reason. Or maybe makes a state run in October 2024, or a federal run in 2025. Would those consist part of his "political career"?

As for the practicality of his proposal, that's a reasonable critique I think. How would you determine it? Not clear, and might cause issues with enforcement. But if those issues can be resolved, the policy itself is a very good one in my opinion. There are apparently thousands of vacant homes in Brisbane. That's enough to make a very significant dent in the rental crisis. Heck, it's enough that even if compliance rates are low, it could still be worth doing to make some dent.

Short term rentals I comparatively agree. These aren't in the thousands, but more in the hundreds. I think it's still worth restricting because even hundreds is still hundreds of real people who could get housed. And also because short term accommodation via the like of Airbnb aren't complying with the same types of safety and accessibility laws that more conventional short-term accommodation like hotels have to meet. This policy (which I think it's worth remembering is in principle bipartisan—the LNP brought in increased rates for short-term accommodation last year, and the Greens policy would just be an increased version of this) is too often talked about as a silver bullet, which it just isn't. But that doesn't mean it isn't worth doing, in combination with a number of other changes.