Is it better to go 100% into ETFs or mix a rental property with monthly DCA?

I need some advice. I am 36 years old, a tax resident of Serbia (non-EU), and I have a 20–25 year investment horizon (with the possibility of Serbia joining the EU by then). I am investing solely for my own retirement, as I won't have any heirs. ​On top of my initial €100,000 capital, I can contribute an additional €150 per month from my salary to start (salaries in Serbia are relatively low), with the potential to increase this monthly amount in the future as things fall into place. ​This leave