Simple, production costs and material costs.
CNC machine time is $150 to $500 an hour. Materials such as Stainless Steel and Titanium prices have sky rocketed since covid. Also, you have to figure in liability costs.
Funny thing, I don't own a Glock of any form. They just don't do it for me.
I won a G29 in a raffle. Hated it. Sold out and bought a XDM Elite 3.8 10mm.
I have guns from a couple hundred $ to ones that cost MANY thousands. They all have their place. Im not a gun snob and will own any gun that works. For example, I own a Taurus GX4 that has been 100% reliable for over 5000 rounds. I have even used it for IDPA bug gun competition. It just plain works.