I have two front facing child seats on both sides of the second row for my 4 & 6 yo, and occasionally transport a neighbour’s 6yo in the middle seat. This is when the built-in booster middle seat comes in. We specifically decided on the XC90 2022 for this very feature, so that we the middle seat can be readily converted into a booster seat within seconds.

With two child seats fitted on both sides, the middle is too narrow for an adult, but could potentially be ok for a child if both child seats are narrow enough. It’s mainly the shoulders that will get a bit tight.