I understood after I watched the brilliant Weber Auto video on it, published 5 years ago[0]. I liked it so much I "gently" encouraged my partner to get a Yaris hybrid, which gets about 69mpg average. It's not unusual to see 80+ on individual trips. She was a little sceptical about having an auto at first, because us Europeans still think it's 1980 and that manuals are superior, but she came around after a few minutes of driving.

To be fair, though, classic "slushbox" autos actually were/are garbage, as are chain actuated CVTs. The hybrid system gets you immediate acceleration like an electric, none of this awful lag you get with a slushbox.

It's hilarious to me that 34mpg is considered remarkably good, though. I know it's a "minivan" but my Golf GTI gets 42mpg and is actually fun and arguably cool. I can also fit 5 people, furniture, and 2.4m lengths of timber in it comfortably.

[0] https://www.youtube.com/watch?v=O61WihMRdjM