Congratulations F4, another milestone reached.
Now that a British passport is no longer an EU passport then that advantage of easy travel and work anywhere in the EU is gone. While living in the USA we went on a 6 month holiday to Australia and we used our British passport to enter and leave Australia simply because the visa cost less.
Some good friends of ours who we’ve known since the 70’s had an interesting experience last year. The wife is Canadian, has been living here for over 50 years and I didn’t realize she never took up British citizenship. They went to France on holiday but were turned away at check-in because France had changed its rules and Canadians now need an e-visa to travel. They went home, went online and got the ESTA(?) needed and flew next day. Cost them a re-booking fee and lost a day of their holiday.
So, apart from little potential gotchas I don’t think there is big advantage to getting British citizenship. Although I think having 2 passports gives you licence to kill. At least that is what I understand from watching the Jason Bourne movies.