On brake fluid changes on Mini's dime, of course, do it. Later, though... that's a good question.
After the pleasure of rebuilding seized (rusted) Volvo calipers and a rust-pitted MG master cylinder on cars I bought used, I don't miss a recommended brake fluid change interval. Brake fluid really does absorb water from the air, and because water is heavier than brake fluid, the water collects at the lowest point of the system--the caliper pistons. It causes corrosion. One reason is that caliper pistons are usually steel and the bores they ride in are not.
I like changing brake fluid myself, and at two years, BMW brake fluid always is brown coming out and clear going in, typically after not very many miles. Not always dark brown, but brown. The brown is corrosion, and the cause is water in the system. So I've always done it per the manual's recommended intervals.
But. Humidity from the air gets into the brakes as fluid from the reservoir enters the lines to compensate for pad wear, and EV brakes just don't get used that much. So the pads don't wear, so not much air enters the reservoir as the fluid level drops, so not much water makes it into the brake lines and down to the calipers. I can understand why someone who mostly uses one-pedal braking wouldn't do the two-year changes.
I may reread this post to talk myself out of it when the time comes!