It’s not a mistake. It’s a tax on physical gamers who will in future have to pay for console + disc drive, thus making physical less attractive.
Also, it controls availability of hardware with consumers being cut off from physical drives on a whim by Sony.
Right now the drive is probably 5x the price it needs to be. Come ps6 release, it will be 10x the price it needs to be and stocks will be low. PS5 drives will not be compatible due to some spurious technical or idealistic aspect (think DS4 pads on PS5).
Separate disc drives isn’t about Sony giving consumers a choice, it’s about controlling the future.
Think about it.