Normally after a console has been out for 5-6 years like the PS4 and XB1, the price is below $300. If a person is willing to pay $300 for one of these systems, then they likely already have one. This is the time period to try to see to late adopters who want a cheaper console.
Basically these consoles need a price cut. I'm not even particularly a fan of either one, but this type of business just seems crazy to me. I doubt they would be selling at a loss at $250-$200 and they already sell at this price during the holidays anyway. Basically their current model is to sell most of their hardware during the holiday season, because that is when these old consoles are actually at a decent price. Why not just go ahead and make the price cut permanent?
In the case of the PS4, I think Sony is just content with the amount of sales they are getting right now and are not willing to sacrifice profits in order to expand their install base anymore. I mean, the thing already outsold their previous console by more than 10% and it still has a couple of years left in the tank. So I´m pretty sure it has already exceeded their expectations and then some.
MS is a lot harder to read though. I mean, with all their talk about "games as a service" you would think they would be more interested in expanding the install base as much as possible. I mean, at the end of the day, the more people with consoles in their homes, the more people would be available to sign their gamepass service. Maybe they believe it wouldn't make much difference? That would be a weird way to look at business.