Buy estate or invest?

Dear Redditors of Luxembourg and beyond, needs your help and guidance:

I live and work in Luxembourg, I’ll stay for another 2 years, until April 2027 (at the earliest) or 6 years, until 2030. I’m 38 years old. I live alone, but I assume my partner will move in with me.

I am an expat and I will either go back to my home Member State (where I have some estate property and my family holds some more) or somewhere else.

Currently, I’m renting a great apartment (excellent location, standard, and comfort - great deal made during COVID) for €1,800, with other costs included + 120 EUR insurance per year.

Here’s where my question about potentially purchasing a property with a bank loan comes in.

The apartment I’m considering costs around €700,000. I understand the down payment would range from €70,000 to €140,000. The standard of such an apartment would be lower than the one I’m currently renting.

The bank loan payment would also be closer to €2,500, and along with other expenses, it totals about €3,000 (or possibly more: loan insurance, etc.). I am checking that right now

This brings up two possibilities: either I buy an apartment in Luxembourg, or I invest that amount (and whatever I assumulate on the go) in stocks, ETFs, and krypto.

I’d appreciate any advice and suggestions.

If you also have any comments on my calculations, I’d be very grateful.

Thank you in advance!