With a cost of living crisis, I should think a cheap, or free - if you're over 60 - bus or train ride for a Londoner would be a good, inexpensive day out. Pageantry; a mood of good will and shared experience; honour for a leader whose devotion to duty and smiling good nature for the public can hardly be denied, and which will act as a pattern for anyone looking ahead to years of responsibility - perhaps for the sake of their children.
If you don't want to understand the monarch's job as a ceremonial one, and you want to hold her personally responsible for decisions of various of her governments, then maybe there is a negative issue, but common sense prevailing, you accept that she has been there to not get involved in politics, to thank ordinary volunteers from all walks of life and to help with greeting other nation heads of state.
I think with a packed lunch and drinks it doesn't have to be an expensive day out and one which would be fun.