Depends a lot on where you live. We tried renting out our home after we emigrated. We missed the boat on the commodification of house prices in our previous country. They're still rising, but nothing like the amount the previous generation experienced. The primary limiting forces are loan interest rates (lower rates = higher house prices) and average salaries (rents usually reflect how much can be scalped from people in a given area while leaving them just enough for food). Unless that country does something dystopian, like introduce multi a generational mortgages (like Japan has), prices have more or less stagnated. Wages certainly don't seem to be going up.

The money you make on the house will also depend upon your own income, i.e. what tax rate you will be on for your rental income. You may not be taking home that much of your rent. The good old days (where you could dump all the rent into a mortgage and claim zero income) are long gone for a lot of countries. This might not be the case if you run all this as a company, but I decided against that, because getting money out was arse.

I currently have a few ETFs, but what you might want to consider is the ETFs your pension is invested into (if you have a defined contribution / 401k style pension). Mine are currently all invested in European ETFs in the vain hope that it may mitigate some of the losses when the AI bubble crashes, and takes the US stock market with it. Your pension will be pre-tax income, so it's a much more efficient way to save. Some countries will allow you to take out a lump sum before you retire, so this isn't necessarily just playing the long game.

Anyhow... it all really depends on where you live & your personal circumstances.