I'm very sad for my friends in the UK. I'm not suprised based on their situation.

The situation with Greece 10 years ago was financially VERY different than the UK with BREXIT. IIRC Yanis Varoufakis gave some very detailed answers why GREXIT would have been better for Greece after a few very painful years, particularly for the average Greek (as opposed to the 1%). I agreed with him then, and without going back to research again, I'll stick by him now.

The Eurozone has advantages and flaws. The biggest flaws are in banking, where countries have downsides with no upsides. That was Greece's biggest problem, again IIRC.