At this point it has become a running meme that single-players games are dying with executives of big game companies spewing this falsity. As a competitive gamer with 16 years behind the controller/keyboard I can say without a doubt that single-player games are still my favorite games. While there is certainly a place for multiplayer games (I still play Fortnite, Rocket League, Battlefield) there is no denying that story and single-player games have a embedded territory within the industry.
So the whole economic conundrum of single-player games has never been proven true nor has the phrase, "Multiplayer games are more financially safe" been proven true. There is simply no proof/research that has solidified those opinions as facts. Not to my knowledge at least. Sure, multiplayer can have more replay value, they can provide more overall experience than a story driven game. But that simply does not mean that single-player games are dying. With the releases of God of War, Breath of the Wild, Horizon, and SM Odyssey there is only proof that single-player games are just as alive as they have ever been! Notice that none of those games have any multiplayer attached. At the same time each of these games provide dozens of hours of content and replay ability. Sure, maybe not 100s of hours like multiplayer games but I can tell you right now that all those games provided more content and replay ability than games like Sea of Thieves (which the development time was quite similar).
My other main issue with people saying these obnoxious things is that there is this one thing that everyone seems to forget: SPEED-RUNNING.
Contrary to popular belief single-player games can be competitive. You can find millions of videos of speed-runners trying to beat their personal best or going for an absurd world record. On twitch there is a charity stream dedicated to speed-runners where I often see 100,000+ people watching and donating money to give the middle finger to cancer. I have seen many games dedicate trophies/achievements to beating games in a certain amount of time. I simply cannot see speed-running dying and thus single-player games will live on.
Anyways, Sony, Nintendo, Bethesda, and various other smaller companies have been releasing single-player games for years. GTA5 didn't have multiplayer long after it was released and still made a huge profit and is continuing to be in the top 10 best selling games of the month. We have Detroit, Spider-man, Days Gone, Ori and the Will of the Wisps, The Last of Us P2, Bayonetta 4, Red Dead Redemption 2, Metro Exodus, Ghost of Tsushima, Death Stranding, Kingdom Hearts 3, Shadow of the Tomb Raider, etc.
If this is not enough to prove that single-player games are not going anywhere then go have fun playing CoD26, Gears 7, Battlefield 6 (do you get the point?)