Bringing the discussion back to the original topic, annuity using leverage isn't a bad idea, but it depends on your use cases.
It's "like property", but only in the perpetual income distribution, but it lacks the "capital growth" capability.
Unless TM Retirement GIO counts.
When leverage is in a different currency of the annuity it is usually a bad idea though...
To keep your analogy of buying a property, it's like if you were buying a house in Indonesia, collecting rent in IDR but taking a mortgage in SGD.
Your mortgage rate in SGD will be much lower compared to the mortgage rate you would have if you had borrowed in IDR. This would give you a very attractive leveraged yield. However, if IDR starts to go down against SGD you would quickly be in trouble as you wouldn't be able to meet your SGD mortgage payments.
Borrowing in safe haven currencies like CHF or JPY for an annuity in SGD is quite similar even if SGD tends to be a stable currency. CHF or JPY usually strongly appreciate against other currencies (including SGD) in time of market stress.