Other than getting you in the shorter queue at passport control, I'm not sure what citizenship, as opposed to residency, would give you ?
We have our residency "green card" and pay our taxes here, which means we have the right to live here full time, the benefits of freedom of movement in he EU, health cover etc etc even with our UK passports
Important to note citizenship and residency are two different thing
You'd get all the benefits of being an EU citizen. Free movement, Healthcare in other countries for example. Being able to vote, etc too.