The engineering praise comes from the fact that if you are taking care of it, you will probably never have to work on it until it's well into 6-digit mileage. This remains consistent through pretty much their entire line with the one exceptional black mark really being the RAV4.
Usually at that point someone puts in a new hybrid battery and sells it to someone else starting out driving Ubers.
I had a Toyota Yaris a couple of decades ago. Very reliable, very few issues. But some routine things like replacing headlights were completely bonkers. You had to wiggle your hand between some sharp metal parts to unscrew the back end of the armature. Sheesh, would it have been that prohibitive to add a few cm of extra space there?
That said, the synergy drive is by design a very robust mechanical system. It has no dog gears, clutch or torque converter. I'm sure this contributes a lot to their long life.
What kills the hybrids is that the kind of people who buy these sorts of "peak appliance" cars tend to be the same kind of people who'll obliviously let some critical fluid run too low. You get orders of magnitude less of that sort of behavior in taxi fleets.
All this assumes proper maintenance, especially oil changes.
Who thought that was appropriate?