And while it is not common that you find a $100k industrial building, it is also not impossible, depending on condition you need.But at a high level, there are a few factors at play: everyone needs a place to live.  

Really depends on what market you're in with material and labor costs 

Then if you end up doing a self directed IRA instead of a Solo 401k from not having any self employment income, you are subject to UBIT rules, which can cost you thousands in fee annually just for the filing depending on the complexity - in addition to the tax owed. 

The seasoning period varies from lender to lender.

Assuming OP has income to offset of course, and depending on other individual factors related to their personal tax situation obviously... am I missing something?

It depends on where you are living, how long you think you will be living here, if 3 years is the minimum but a good chance it’s gonna be longer bite the bullet & buy, if 3 years is the max it’s probably better to just rent, regardless nothing will cash flow, the big benefit is locking in your payment, but the value of that depends on the timeline, as far a where that would really depend on your preference’s in price point, do you want urban or suburban living, how big a space, how nice etc?

Very nice, Florida provides a strong STR market depending on the area you buy in.

If you own a vacation rental in the Smokies, it might feel like demand is soft. And it is soft. But compared to what?
As I look at my company's pace report, most properties are merely reverting back to 2019-esque num...

They can vary widely and significantly impact the overall cost of homeownership.

You miss out on any appreciation and tax benefits, and a lot depends on the quality of who you rent from, but I don't know of any way to more cheaply enter into a new market and learn it.