The hardware was fine (apart from my Vita which would throw errors about the SIM card slot all the time). But they didn’t immediately displace Nintendo DS or 3DS, so Sony weren’t really interested in keeping them alive.
If this thing can’t even play PS4 games, it’s dead on arrival. Having launch access to a huge back catalogue is the only thing that could make it interesting. Even then, a lot of the best PS4 games already launched on PC. How are they going to differentiate themselves from the Steam Deck?