They "did", it used to be a narrow two lane death trap that averaged two or more fatal accidents every month between 1992 and 1998. They added two additional lanes with a huge median separation. That project took years to complete. (New funding) has been secured to add lanes and improvements from Issaquah/Hobart east to Tiger summit beginning in 2025.
It's actually much safer now than it was 25 years ago. But I do agree w/you (to an extent).