> I am a citizen of country A but live and work in country B [...] I also have to pay taxes to country A, which involves more paperwork.

Isn't that the case only when country A is the USA? AFAIK, nearly all countries in the world tax only residents, not citizens, so in most cases you'd only have to fill tax paperwork (and pay taxes) for country B.

Only if you're only talking about income from work. If you own property in country A which you rent out while you live & work in country B, then you probably still owe tax on that rental income in country A. (but it will depend on the exact wording of the relevant DTA if one exists)

And since you are now filling in two tax returns for different countries, with different tax allowances across rental income and work income which interact in decidedly non-linear fashion, you probably need to make sure both country A and B have no confusion about where your work income was earned.

Having spent the last 8 years obsessively counting days across the UK and Finland (and every other country I have visited) exactly to account for this scenario, I am very sympathetic to attempts to solve this problem space!