Exactly! There was a game released some time ago for XBox and PS4, and it accidentally included cross-play. One or both of the companies (Sony / Microsoft) had a fit and a patch was shortly put out to "fix" this terrible "bug".Cross platform isn't a technological issue, it is a corporate ego (not FD, usually console companies) and bureaucratic issue.
The same goes with keyboard support on PS4. ED actually had some very minor keyboard support on PS4 that was likely copy-n-pasted from PC code, and as soon as Frontier discovered this, they "fixed" the problem (way faster than they fix bugs that matter BTW). This is proof that these "limitations" on consoles are dictated policy, not an issue of hardware or OS anything like that.
Sony being Richards (not just regarding consoles, cough Spider-Man cough) is one of the reasons I'm starting to have second thoughts about upgrading to the PS5 when the day comes.