A lot of people parrot that, but it's not really true, at least on PlayStation. The vast majority of PlayStation games are playable from disc without any internet connection. Of course, you won't have the latest updates and the game may have more bugs and worse performance if you aren't connected to the internet, but you can still play games to their completion.

I know that from a legal standpoint you still only buy a licence and don't legally own the data on a disc, but that doesn't really matter for the purposes of playing a game. You can play when the servers are down. You can play when your account gets hacked or deactivated. They don't have a way to take the game away when you aren't connected to the internet (even if they can legally revoke it).

And even if it would be "just a download key", it's still a key that's transferrable and that you can share or sell. So in terms of ownership it's still much better than a fully digital license even if you completely ignore the fact that it's still storage media that apart from a few exceptions still contains a fully functional copy of the game.

For me personally all my games I play on Playstation are on disc, and I bought them all used. For me the discs are the reason to get a console. I live in an area where one ISP has a monopoly so I have to live with a datacap too small to be able to download even a single modern game, and datacap expansions frequently being more expensive than the game I'd download with them. And on the used market the games can be pretty cheap. So all my games on PlayStation are on disc, and I bought most of them used.
If discs are not available for a game, then I pretty much always can get the game way cheaper on PC than on the PlayStation store, and on my PC it'll run better too, so then I have no reason to buy it on PlayStation instead.
But I do realise I'm a minority in that regard, at least when you look at global scale.

I got it for dvds.