As much as I'd love a new Valve game, why fix what's not broken, financially speaking? Valve/Steam definitely have plenty of other problems that I'd love to see get sorted out, but they're making tons of money.
With games, you seem to have two choices...
Do you want a game now, or a genre defining masterpiece that maintains playability for a decade later?
Now an actual Half-Life 3 in VR, on the other hand ... if executed properly that would literally go into the history books as launching the entire next generation of gaming, more different in kind than even the original transition from sprite-based to truly 3D-rendered environments.