"Perfect is the Enemy of Good", as happened with Duke Nukem III.

Duke Nukem 3D was a huge hit. You must be thinking of Duke Nukem Forever, which would have been the fourth game in the main series.

Sometimes when I think about how anxiety-provoking it must be to even _think_ about making Half-Life 3, I wonder if Valve might not be better off building something that completely defies expectations about what "Half-Life 3" should be instead of trying to meet those existing expectations and then inevitably disappointing a huge number of people even if they produce something pretty damn good.

What could it look like instead? Anything! I think a Divinity-style RPG Half-Life would be heaps of fun. Or a hero-based RTS that still has Gordon Freeman centre stage. I think basically any genre that can tell a story would be fine.

Of course this guarantees disappointing a lot of people, but I feel there's a lot better chance of Valve producing something creatively worthwhile this way than trying to make a "vastly better Half-Life 2", which is what most people seem to be waiting for.

This pretty much exactly describes Alyx. They defied expectations about what Half-Life 3 should be and disappointed a large number of people (who were mad that it was VR exclusive) despite producing something incredible and unprecedented.