The effect on Xbox was not instant, it took years to notice the decline and they never recovered. The same will happen to Sony.
The numbers look good now but by the end of the gen it will slow down a lot faster and it will be too late to get back these customers.
Many customers are wondering why bother getting a PS5 if all the games are getting announced on PC one after the other? Same interface, trophies and dualsense integration.
Xbox has been in decline since the 360 days for many reasons, and not because having their games on PC. It's a mixture of having worse and less exclusives than the others, having not some but all their games on a game sub and PC DAY one, having way less support regarding 3rd party multiplatform games (like titles available in PS and Nintendo but not Xbox) etc.
PS5 hardware sales will decline this year because as happens in all consoles, after its peak year it gradually will sell less units per year until it gets discontinued around 11-12 years after release (2031-2032).
PS5 will continue breaking records as usual, and its software/addon/game sub sales will continue growing. Plus they'll continue breaking thier PC/off-console revenue and profits records (and same for SIE). Things like the library that users built on PS, great and exciting games released on PS that won't be available on PC -at least for a couple years-, and well, people simply prefering to play on console due to preferences (like playing in the sofa/tv, cheaper hardware, more plug and play experience, etc).
A small portion of players may move to PC, but would be more than compensated by new players who would move to PS thanks to getting new fans via PC ports, movie/tv show adaptations and different Asia focused strategies like parterships with many top or indie Asian companies, which will also provide more exclusivities with a new flavor (case of Stellar Blade or ZZZ).
They missed their target by 4 millions or more this year and that's with SM2, Helldivers, FF7, Ronin and Xbox games. There's already a sudden slowdown they were not expecting.
They missed their hardware target in the previous year, before Helldivers, FF7, Ronin and Xbox games were released. And not because they had bad sales (they had their best Q3), it was because their target for the holiday having only Spìder-Man 2 as big top seller exclusive that quarter/year was too optimistic.
Even if missed their target number in hardware units, they still did perform great in hardware and kept breaking records in the other areas, like revenue in all parts, active userbase, etc. Once they complete paying coss of previous acquisitions, and release more PC stuff, unless the hardware components costs get pretty wong, they'll go back to break records with profitability too soon.