The console market isn't tanking, it's growing. Slowly but keeps growing, as also happens with PC or mobile.
PS Plus is a profitable business model: to put there mostly old games that are no longer selling generate extra revenue/profit, and putting there old games doesn't affect sales, which keep growing. GP instead is a suicidal model because putting there many imporant games first kills the sales of such games and also other ones that aren't being played/bought, and also because to pay a company to put a game day one isn't the same than to pay that same company the same game 4 years after launch.
Regarding Xbox, it's declining and its market share keeps getting very small but should be included like the other ones to keep the chart consistent when comparing to previous years.
Who said Steam generates $9B/year? Not Valve, and the serious market researchers like Newzoo and IDG say PC makes around $40B/year instead (and everyone assume a huge portion of it is from Steam).
And PS game revenue (its games + addons sold on PSN, which is what should be compared to Steam) doesn't generate around $25B/year at all, Sony reported this. That figure is what the entire SIE does, including their PC/Xbox/Switch games, movies, hardware, accesories, game subs and so on.
As seen above, IDG says PS+Xbox+Switch generated in CY22 $12B in addon content + $9B in digital game sales. $21B for the three consoles. You can add here physical games if you want, making a total of $30B in CY22.
What SIE made, in this case FY23 (not CY22) from PSN is 1082967M yen in addons + 851619M yen in game sales = 1934586M ($12.34B)
If you also want to include the 180250M ($1.14B) from PS physical games, then the total goes up to $13.48B. Which as can be seen htere is a substantial increase from FY22 and I assume even more compared to CY22.
We don't know the game software made by Steam (game + addon sales), but should be an huge part of the around $40B game software reported by Newzoo and IDG.