The reality of the situation is this:
No one who plays a 2-year late PlayStation Studios port to PC is going to buy a $500 console to play the sequel on a vastly inferior system.
You say this as if EVERY PC gamer has better-than-PS5 specs in their setups. Most don't. Go check the Steam GPU & CPU usage charts, they will back this up.
They'll just wait for the sequel to also come out on PC while they chip away at their backlog.
This might be true and it's something I think SIE need to be concerned about WRT their porting cadence already established on PC, but not because most PC gamers are rocking mega-powerful rigs.
Very few people who own a PS5 are going to spend an insane amount of money to build a PC that can run games better than that console.
And most won't need to. In fact, if a good chunk of the casual or mainstream types who end up buying cheap PC gaming devices (because of slower adoption by hardcore & core enthusiasts on the console side early on) do so in lieu of console, they likely would be 100% fine with gaming specs below a PS5.
Casuals and mainstream don't care about power and they aren't obsessed with top performance.
If Sony is porting these games to PC anyways, doesn't it make more sense to have their PC releases also benefit from the marketing dollars spent on the console version's launch?
No. For starters, the only vested interest they have on the PC side IS the game, whereas with the console they have the console hardware, the subscription service, 3P sales off PS Store, MTX add-ons for GAAS titles (1P & 3P), peripherals etc.
Put it this way: a $70 purchase on PC is worth substantially less to SIE than a $70 purchase of that same game on their own console. So until they shore up enough vested interests in the PC space to match what they have in console (specifically WRT profits, but revenue is also important), Day 1 PC for all of their games will just incentivize more of the high-ARPU hardcore/core enthusiasts to opt for PC, the platform with less vested interests for SIE.
And let's face it; as Helldivers 2 is proving, the PC buying base simply isn't big enough to offset the potential revenue & profit drifts. Even if the split is something like 30:70 in favor of Steam for a game like HD2, those PS5 customers are still more valuable to SIE because they're the ones who've also bought a PS5, and likely bought several games just this year alone that SIE are getting 30% profit cuts from, are the ones that sub to PS+, likely bought a PS Portal etc. The Steam customers aren't providing ANY of that additional revenue or profit for SIE, and this is Helldivers 2, a GAAS title.
So in what universe does doing Day 1 for non-GAAS titles (specifically AAA tentpole) make sense just because "marketing budgets would align", when that isn't driving enough PC people to buy-in to produce comparable ARPU value to SIE as the console buyer? And why would SIE risk having high-ARPU console owners switch their primary platform from PlayStation to something like Steam just for a few extra PC copies to be sold?
Square Enix appears to be arriving at this conclusion.
Square-Enix appears to be arriving at a lot of things which may or many not include Day 1 multiplatform releases for games like FF. I still assert there were other things related to their release scheduling, and with FF in particular, inconsistent quality ranges stemming back to around FF XIII.
FF also has had issues with consistent game design decisions, and alienating larger chunks of the fanbase jumping between major installments because of certain changes even if the games themselves were quality. If none of that stuff is truly fixed, then simply slapping the next big FF on other platforms Day 1 won't suddenly cause a massive explosion in sales. It'd help, but wouldn't address problems at the root.
So whatever a Day 1 multiplat strategy would fix, would be hampered by that.