Prime Evil Collection Diablo is the thing I’m looking for on PS4. I just want to make sure things are like I want them. Can I play Diablo 3 on single player without a need for a paid subscription from play store? I always play solo on PC, so I will play solo on console. I assume there will be some updates and the internet is needed there, so I don’t mind that.
Plus, can I play D2R by myself on PS4? I mean, also without a subscription?
No subscription is needed at all unless you want to save your characters to the Sony cloud.
Thank you very much Deadly Mouse!! 
Well… “True” but you also loose the ability to play online with a real group finder that works. Also, I dont understand why everyone doesnt have playstation+, you really get a ton of stuff for the 34.99 a year (if you buy at thanksgiving sale) I already racked in over $5,328 in games (FREE) since I was a member. Its crazy how much stuff they give you (especially if you have a ps5) 
Good.
I only play couch co-op.
I also have 0 interest in any digital game. Especially if that is the only way it is released.
Well speaking first hand (having a ps4pro and a ps5), you will NOT want to play d2r on a ps4. It’s very bad and you will insta die in the final act2 boss (the loading on a ps4 is so bad, you spawn in dead). on a ps5 its a nanosecond to load so you can actually dodge the first big incoming deathshot.
I believe you would need an online sub for d2r (it has to check in to battlenet (even for solo) and if there is a “queue” you can opt to play “offline” but you cant select “offline” as an option when you load.
Oh my!! That sounds bad. I ‘have it’ for PC, but my damn computer is too old to run it, so I thought I’d try it on PS4 
You don’t need to have an online subscription to play D2R offline. Battlenet just checks your credentials whenever you start a game. You then choose “offline” when you play. When you set everything up with Battlenet, make sure to finish it. Otherwise Battlenet will ask you to verify your info which is annoying when you’re starting a game. It took a few times to verify and it took a few hours until my character that I’ve been working on showed up in the menu. I had thought my character was deleted in the process but thankfully it was there.