Because, unless this changed, consoles are loss-leaders. At least back in the ps2/gamecube/OG Xbox, the systems were sold at a loss and the money was recouped on controllers and games.
Can’t use a ps2 controller to play a ps2 game on a ps2 without the ps2 console.
If this is still true or not, I don’t know. I do know that the ps5 with an optical drive cost $100 more than the digital edition. I also know that the drive does not cost $100 and sincerely doubt the labor makes up the difference.