From Sony's perspective, they profit from the hardware sale, then they profit from some software sales. Both are better than not having those fuller profits. Profits are often about accumulated nickel-and-dimes.However, there's also a downside to that if the person that owns a PS5 and a gaming PC only ever buys the occasional PS5 exclusive because that's the only reason they own a PS5. That means that PS5 isn't contributing a lot to Sony's bottom line since it's not generating revenue from 3rd party game sales.
This is not a downside, this is still an upside. If the situation were reversed and this was about Microsoft, given they clarified at the tail end of last year that there were still taking significant ($50-100) losses on Xbox console hardware, that would be a downside. I.e. it's costing you.