7 years later, nobody gives a shit about all those xbox trolls who were saying "PS4 has no games" (like they always say at every generation, btw), or "at least the Xbox One has games".
I see your point. It's not about launch, it's about the proven track record.
PS4 really didn't have much to offer for the first half of it's lifespan, it didn't took off until 2016 once the exclusives started to show up, until then it had to be carried by PS3 remasters, 3rd party cross-gens, and indie ports from PC/smartphones, which anyway didn't even matter as the 399$ price tag alone carried the console so damn well. XB1 on the other hand, despite the popular belief, I think it had quite a solid lineup within those same 3 years or so - Forza was there, Gears were there, Halo was there, Titanfall was a fucking blask, so was Sunset Overdrive, and so on, which again, didn't matter much since most people went for the cheaper console anyway, where their friends already were.
But if speaking strictly about games output, it was that ~2016 when the tides have turned, when Sony's devs were finally finishing their games, whereas MS lost its steam, and it all didn't happened without a reason - that's just how long it took, and still is today, to make games. PS3 was heavily supported until the very end, so once the devs finished those PS3 titles they needed time to focus on PS4, rewrite/modify the engines first and foremost, and finally develop the games, whereas MS at the end of X360 life were focusing on Kinect and other bullshit, meaning their AAA devs had that extra year or two head start.
Now fast forward to today, and we are seeing basically the exact opposite situation, 2013 in reverse so they say, where if we look at upcoming PS5 lineup, 2021 and 2022 looks fucking stacked, basically every 1st party studio will release their PS5 title in that time (unless there will be multiple delays yet again), but the question is - then what? Because they will need years again to make another games, and I'm not even taking quite possible delays in consideration, and we are talking abut cross-gen PS4/PS5 titles here, not to mention sequels - another R&C, another Spider-Man, another Horizon, another GoW, another GT, they already have solid foundation, basically half of the work is already done - the engines are there, the gameplay mechanics are there, animation/physics/AI/sound systems are there, that's why they can make those early PS5 titles so fast, but if any of those studios will want to make something truly new, then the time needed to develop the game will greatly extend, take Sucker Punch for example - it took them 6 years between inFamous:SS and GoT, because it was something completely new, SSM same deal - GoW took them so long because it was basically a completely new game with just and old title and main character, but everything from gameplay, universe, story was completely new. So the first 2 years for PS5 look very optimistic, but after that, I believe it will be eaither sequel fest or a long dry period before new IPs show up.
MS on the other hand is obviously the one who needs extra time after launch this time around until all their recently acquired studios start pumping out the games, 2022/23 is when we will start seeing those acquisitions doing their job, but until then, it's all about 3rd party multiplatform titles doing the heavy lifting..