But that doesn't really answer my question: what mitigations do other states have now that Florida doesn't?
Florida's vaccination rate is about middle of the road for the country, so it's not an extreme outlier there. I can't find anything that says Florida had an extreme number of excess deaths either. Most things I can find show it middle of the pack there too (I'd be happy to be proven wrong on this, but the CDC's excess death page is wonky and I couldn't find a good way to look at their data, so found other articles).
Florida had a thing last summer too, at almost exactly the same time period, where cases spiked super high when the rest of the country was fairly low. The pattern is almost identical.
BTW, this is a bit of a baity headline:
DeSantis bucks science, suggests one dose of Pfizer vaccine may be enough. At the time the article was written, it was up for debate whether it might be better to just get a first shot to as many people as possible when doses were limited to get more people some protection rather than none, which is sort of what I believe the UK did, so it wasn't a crazy idea, even if now it doesn't seem like the better way to do it.