Can someone explain (Micro)Strategy's business model?

Over the past few months I have been watching/listening to a lot of Saylor's presentation. His latest speech was at CPAC.

Can someone explain in concrete terms the business model behind Strategy?

The way I see it now:

- It works as long as you can keep borrowing at low interest rates vs projected BTC price increase.

- This is not an actual business. It needs the underlying asset to appreciate indefinitely. Unless Strategy becomes a bank and start offering loans in BTC.

At the same time he argues that the US should buy BTC to solve its debt problem. He suggested that securing between 4 to 6 million BTC would be sufficient to cover the entire US national debt. Wouldn't the US need to sell their BTC to clean their debt?

Or would they just give away their BTC to their creditors?

Considering that the value of BTC depends mostly on people's appetite for it, wouldn't this affect the FIAT value of BTC if the US reduces its exposure?

Short term this works well. Get the US to buy BTC for their reserve --> BTC price increases.

Long term, I don't understand the play (maybe his time horizon is shorter then). So maybe someone can explain it to me. Apologies if this was answered before.