I upgraded from a T3 to a T4, mainly because of the IBIS (I was experimenting with vintage lenses, and none of them have OIS), and because of the battery life. With the T3 I always felt I was in Austerity Mode with quite a lot of the battery draining options switched off so I could get reasonable life out of it. The flip side is the T3 batteries are pretty small so it's not a big deal to carry around spares. I can't say I've really clocked the autofocus being better, I didn't have them at the same time so I couldn't make a comparison. The flippy screen, well I came from Canon, which have the T4 style screen, but I got surprisingly used to the T3 style, on balance I prefer the T4 but I'd have to say the T3 style would be better for discreet street photography.
BUT I think I fitted into the 'more money than sense' category. I had always wanted a T4, and I traded my equipment in just as lockdown was announced. Fuji announced delays to the T4, and also hinted the price might rise even higher, and I thought the camera retailer might go bust and I would risk losing all credit they were holding, so I jumped and bought a T3 instead. And I'd have to say, although I'm very happy with the T4, I like the weight and the slightly bigger grip, it is £500 more expensive than the T3, half the price more.