Almost every time "regular" people get in trouble for piracy, the reason is that they seeded something, a copyright law firm (or their contractor) noticed it, noted their IP address and then either went and got the real life address from the ISP so that they could send you "the bill" or they made the ISP send you something, depending on where you live really.
That means, as long as that that IP address that shows up on that law firms screen isn´t actually "your own", isn´t immediately traceable to you simply by calling up your ISP, you´re already one step ahead in the game.
That law firm might still try to contact the owner of that IP though, either to send them "a bill" or to get them to rat on you. And that´s why it is important that your VPN provider operates in a way that allows them to simply ignore that. Either by operating out of a country that doesn´t mandate them to "help finding you" or by simply not keeping any logs of what actual IP was connected to what VPN IP at what time.
So if you have a VPN provider that maybe operates out or through a country where piracy is legal or has proven through audits that they couldn´t rat even if they wanted, you´re highly unlikely to get into any trouble.
If the game actually does something useful with that connection, I don´t have a problem with it. Examples:
However, sometimes the always on is just a way for the devs to battle piracy. In which case its hurting the actual gaming experience.
I´m not familiar with Diablo 4 to be honest. So, in my understanding, the fact that it need an internet connection alone can´t be the reason for not being able to pause the game, right? There must be some real time interaction going on between your "world" and the worlds of others.
EDIT: Hm, I read up on it for a second and it seems like there is a portal that you can use to teleport to a safe place? A town? Supposedly you can even do that from within a dungeon AND even teleport back to the same place?