If you take up the passport you're not taxed based on Citizenship like Eritrea Or the USA
If you're not living in Sweden you're not taxed on income you make outside of it due to you not having residency there
So it's literally a free passport if he wanted to take it up
Polish citizenship since I was born here
French citizenship since I live her for 10 years
I do not have to take that dual citizenship, but I mean, it's always cool thing to have. So why not. I would take 10 different citizenships if I could tbh.
Pratically could get citizentship easily from any nordic country, For some countries like norway I would have to give my own away but I could get a swedish citizenship + finnish
Still no point since finnish passport is the strongest in the world together with some others