I'm probably did a post about this before so apologies in advance. It just seems to be the 2016 and newer models have a very low seat height. My brother feels and I seem to agree it's better for your hips to be higher than your knees when sitting in the car for your back. I have to put the seat up so high it almost feels uncomfortable due to the way the seat moves/positions one in in the Prius. I don't think I have been in a car with such height adjustment, the seat can go so low and so high. Issue is two fold it seems to me. As seat goes up it moves the seat forward a bit then as it goes down back as I recall. It seems this might be due to the new body frame design used by Toyota and I am not certain I like it for best back support. So am I crazy for thinking this and do the earlier year models sit better? Sadly if they did I would not want to buy the older models due to the advances provided in the 2016/2017 design...excluding the 2016 seat adjustment/feel. Also sad is the new 2018 Camry nybrid might likewise have the same issue though since it will be a large car maybe not so much seat wise. Would hate to take a bath and trade over to a 2018 Camry hybrid though slight chance I would.
To your comment about the seat height adjustment moving the seat forward while raising the height, yes that's what happens. Prius has done this all along, including Gen 2 and Gen 3. But then all you need to do is run the seat backwards to compensate. Of course, you only want to make seat adjustments while stationary, i.e. not driving. If you need to make a large adjustment, try standing outside the car while moving the lever. It will be easier since you are not lifting your weight while raising the seat.
That's not uncommon. The worst was one of my cars which dropped the front of the seat slightly as you raised it - with no tilt adjustment. Not sure which car. And seats seem to be set lower in cars nowdays than they were a couple of decades ago.
I think that the Prius itself does that. I have noticed that increasing the height causes the seat to tilt further forward forward, and decreasing to tilt further back, not to actually move the seat back/forward. I think if you have a Prius with electronic seat adjustments the tilt is completely separated.
Gen 4 did lower the hip point, yes, although that's not necessarily bad on the back, you just have to add recline angle to compensate if the hip angle isn't comfortable. I think the logic was that people who prioritized a high hip point are buying crossovers instead. So, lower the hip point, make the car handle better, and try to get a different market.
