You must have missed the entire PS3 gen where most of their games had robust MP, and some liek Res2 were literally a poor CoD copy-paste. Sony already wanted to jump on the bandwagon looong time ago, but they failed to establish any meaningful community and ultimately settled for SP-only games, but as they said again and again, this kind of model doesn't work anymore, the cost to profit ratio is simply way too high, so they want to yet again try to join the MP party, and Fortnite has nothing to do with it. It has a large userbase sure, but it also followed suit the already established market trends, which as I said, started with CoD, specifically with MW2 which not only single-handedly raised the games price to 60$ for the rest of the gen and broke all possible records while doing so, but also showed that you can sell people just a few maps for 15$, that single game, that moment was when all the gaming world took notice and publishers realized that MP and post-launch content is where you can make absurd money for little to no input, and they started doing exactly that. In a similar way, Sony realized that MS has been charging money for P2P online for entire two generations, getting free money for nothing, and Sony decided to do exactly the same with PS4. So long story short, Sony is just yet again seriously late to the party and is playing the catch-up game.
And no offence, but Sony would be foolish to even dream about Fortnite's numbers, first baby step into the MP/GaaS business would be IMO something like 2-3M playerbase year after launch, because there's no GaaS if there's no community just months afer launch. UC4 sold in 15M copies, and how many people were still playing the game by the end of the same year? Exactly, barely anyone remembered the game anymore. Granted, some games may seem dead shortly after launch, only to make an outstanding comeback and skyrocket in popularity, we saw that multiple of times times already, but that needs patience, time, and faith, and I don't think Sony has any of it, not under Ryan who after one or two quarterly reports will most likely cut the game off and move the whole dev team onto something new, and you just can't establish any long-lasting MP franchise with such approach, and buying Bungie won't fix that. The other issue is that Sony's devs simply lack the expertise in MP field, which again, they openly admitted recently when acquiring Bungie - all of the devs who got into this whole MP/GaaS model during PS360 gen have learned the hard way, years after years how to be really good at it, for example back in the PS360 days just a simple patch took at least a week to implement because the patches had to go through Sony's/MS' QA processes, and again, it was IW and CoD who figured out how to deploy hotfixes on the fly, the very same day, without the need to send anything to Sony and MS, and again, everyone else copied this solution. Whereas Sony's approach? Delay. Just... delay everything. Bugs? Delay. Matchmaking issues? Delay. Party crashes? Delay. Now, at the end of the day, after those 5-6 years or so you do get this perfectly polished game that doesn't even need a day one patch, but that's just not how a live service works, you have to be be able to act right here, right, otherwise gamers will eat you alive and move onto the competition's product and won't give you a second chance when the sequel arrives. That's why BF is able to stay afloat after its disastrous launches - DICE just constantly keeps working on them no matter how much people on the internet shit on them, and at the end of the day the results do the talking. Post-launch content isn't the greatest on Sony's side either, they basically drop a single DLC for their games and that's it, feels like they never really have any plans for long lasting support for their games to begin with, just this one add-on soon after launch while the game is still hot.
So all in all, I think this generation will be a really tough test for Sony and their studios, like yeah their consoles will sell, yeah their SP games will sell, but if they want to expand into multiplatform publishing, MP games, GaaS model, online services, they have a lot to learn, while the time to learn was 15 years ago already... Many more experienced teams in the online field have tried to chase the online/GaaS craze but have fallen, and Sony that's been stuck in SP, TPP melee-based story-driven games is so far behind everyone else I honestly cannot wait for their first MP-oriented game to show up, to see how it does. Seems like Factions2 will be that game.