It's not even just continuity between devices that it lacks, most times when I plug my iPhone into my car's USB port, it always starts playing the library at track 0 (alphabetically). Normally I could avoid this if I open the Music app before plugging it in, but it would not always work.
So one of my favourite things about Spotify is that this doesn't happen.
However, unless I have the Music app still installed on the iPhone, the car's entertainment system doesn't show what's playing with Spotify and most times when I plug it in it plays from the Music app instead of Spotify and I have to switch apps. So I installed the Music app again and sync'd a single "silent" track with an exclamation icon album art and a track title saying "Switch Apps".
It's really annoying that when I had to buy a new car in 2019 after my old one was written off, that Apple CarPlay wasn't available in Hondas in South Africa except in Civics and CRVs or better, even though in other countries it was. I'd been holding off buying a new car until CarPlay was available and been telling the sales reps as much each time I'd look while dropping my car off for a service.