Additional points that are ignored:
There's not a clean split between "digital buyers" and "physical buyers". There's digital-only people at one end, people who buy physical wherever possible at the other and then a bunch of people in the middle who mix and match. I know plenty of people on PlayStation that aren't of my ilk, they're not gaf users or the like, they're not hardcore gamers or nerds like us. They're your average joes, many are primarily digital but they all still have some discs. I don't know anyone who has entirely digital. I'm sure there are plenty and this is a small sample, but it's a varied sample of pretty regular consumers.
Also, there's the matter of choice being important. Many people are mostly digital or even all digital but still choose the disc sku of their PS5 because they still like to maintain the option. There's a 17yr old kid next door who's your typical fortnite kid, he saved up to get his PS5 himself a couple years back and he purposely saved up the extra for a disc drive version because even though he's 99% digital he wants the option. We're all looking at software, but there's simply the matter of being able to maintain a choice whether or not you ever exercise it. Most people still choose the disc capable console when they have the choice and will pay the premium for it. That choice is a core appeal of PS consoles.
This isn't for eg. a case of of say, ~75% of gamers only want digital games and consoles because that's the proportion of digital purchases. It's more a case of 50-70% still want hardware capable of playing discs and that group consists of people who are all digital, people who are all physical where possible and many who use both. In turn, while many people will not doubt fold, this is likely gonna piss off a larger proportion of people than you'd initially think. It may not be the reason most split on PlayStation, but it could be a straw that breaks the camel's back. I've yet to encounter anyone in real life that is all that thrilled with the PS5 generation to begin with, frankly most think it sucked and are already considering just riding out PS5 'til the wheels fall off on their interest in gaming or moving to PC and/or even Nintendo(?!).
I believe there's a fundamental issue with these businesses as they progress, the core, original teams leave and it's almost entirely pure money men ruling it. Every element of the business comes under close scrutiny, everything becomes a victim of individualisation and over-metrification. Whether that be one department over another or one format over another..
The older bosses had an instinct for the overall brand and a much more holistic approach, there may be departments or components of that business that are not particularly lucrative in terms of the pure financials; and in some cases they may cause a direct loss. But closed console platforms (particularly PlayStation) are one of the best examples of a business/platform/ecosystem where you have to consider the many ways in which every moving part adds varying types of value. Just perceived value and brand identity can be important. again, it's holistic and it needs people at the top who understand this and have the instinct for what is vital or not. Not people who will cut everything that doesn't pull its weight in a direct financial sense; quite often with goals that are unrealistic these days. Some things should simply be considered a cost of doing business and butchering them is incredibly dangerous, particularly in an industry that is very much momentum based.
I wouldn't be all that confident in Sony's ability to run the numbers either, you only need to look to Bungie and Concord to see what a clusterfuck they can get themselves into. We also see folks like Shawn Layden say this is probably a pure spreadsheet decision more than anything else. Which is a terrible way to make decisions like these. A spreadsheet or something like it can't account for much other than the numbers and it's just not that simple, there are far more organic, unpredictable forces at play that requires someone who either knows the industry or at least has a respect for it.
I also suspect that a large number of those people who are pissed off about this are longer term PlayStation fans. That core userbase is foundational, they're less fickle and more reliable as long as you treat them reasonably. The 14yr old kid who needs his next dopamine fix or even the 30yr old guy who's lost value and reverence for the things he interacts with, Sony can rinse them in the short term, but they'll disappear in the drop of a hat when they see a new shiny thing or just get bored. The quality and consistency of a customer is sometimes as important as the quantity. Even if it's just 10-20% of players, they're a handy buffer when things go wrong, all they cost is a little reason and respect.
Sony seem to be steadily stripping back every part of their identify in an effort to achieve predatory ideals and increase the bottom line by a few percent. Some things just need to be non-negotiable.