Because I was able to get a better QoL elsewhere in the EU.

The average worker in The Netherlands has one of the best QoL compared to average workers in other countries. But the Dutch income leveling and benefit system makes it so a high earner doesn’t have a significantly better QoL. Someone earning €30k has roughly the same spending power as someone earning €50k. (edit: net income after tax and benefits is €42k versus €47k for those two incomes but the person earning €30k has access to cheaper government housing)

In other countries, earning more gives you a better QoL.

It gives you more things to buy, doesn't it? That does not necessarily translate to a better life.

I believe OP is saying that while QoL is great in the Netherlands, it has an upper bound. I suppose that he has access to resources that could provide an ever higher QoL in other countries. For example, in the USA, QoL can be good if you're a millionaire and gets better as you acquire more resources.

Unfortunately, there's no QoL lower bound in the USA, either.