I'm not attempting to start a row here and I generally agree with the comments in this thread but I'd argue that 2 Grandchildren and two adult spaces do make it a 'Family' car. We've become used to huge cars that we drag around mostly with just a driver on-board especially when going to and from work. I realise the boot isn't huge but 90% + of the time I use the UX it's more than adequate. I've sat in the back, with a Grandchild in one of these huge modern safety seats, and I had no issue with leg or head room and I'm just over 6 feet tall.
I moved from an NX to the UX for the very reason that I couldn't justify having such a large but wonderful vehicle that was going to sit around most of the day.
Even though there is a view on this site that the UX isn't a 'real' Lexus I think they are an excellent car with many benefits in this modern and expensive motoring age.