https://www.pushsquare.com/news/2020...ile_this_month
Looks like PS3 and Vita are pretty much confirmed to be on death's door now.
You will only be able to browse/purchase store content via the consoles themselves (I've been told it's hell to use the store on PS3 now, but can't confirm that myself), not via mobile, PC or whatever.
Rumour is a lot of servers will be shutting down soon.