I assume you mean "you" in the general sense.
Just for clarity 25% isn't for me personally, in fact as I might have mentioned on the "Free Now Gone To Shite" thread I opted out of that one at the earliest opportunity. I don't cover any of the enhanced commission fares for Free Now having opted out from Hospitality jobs years ago and I've never covered a DAP pick up for Free Now.
I don't have any problem with fixed fares. The taximeter is a relatively new introduction where I generally passively work these days and I find that north county folk, in particular, like to know what their taxi is going to cost in advance, particularly if they're travelling a reasonable distance, hence with that information they will use more taxis. Uber's rates, in my experience, are currently set as close to the taximeter as makes no difference to me.