By published ETRTO numbers, the 27.5 bead (584) is 4.5% larger than 26 (559).

To find mounted tire height & width, you have to read test reviews. I've never seen such a review show that a 27.5 tire to be more than 5% larger than the same tire model & width in 26. But of course, no one is doing those comparisons anymore, because new 26" bikes are nearly extinct outside of department stores.

My first guesses as to why you like your 27.5 better than a 26 would be that you have a better bike, better tires, and better setup. Those are real things that could and probably did happen. Less flattering would be simple confirmation bias - a consumer getting something new expects it to be better, so they often feel that it is better.