Ori didn't already have 3 clearly numbered sequels.
Ori 1, Ori 2, Ori 2 episode 1, Ori 2 episode 2...
It's literally just naming conventions. You don't consider Bioshock Infinite to be Bioshock 3? You think people didn't considered Code Veronica X to be Resident Evil 4 at the time just because "it didn't have 4 in the name"? Shit, the creators themselves intended for that game to be "the true sequel to 2" even though Resident Evil 3
already existed. The numbers mean precisely nothing. Last year we got Call of Duty: Modern Warfare, which was actually about the 27th CoD game, not to be confused with Call of Duty 4: Modern Warfare, which was actually more like the 8th CoD game, and it also wasn't a sequel to Call of Duty: Modern Warfare 3. It's
meaningless.
They could make a non-VR game where you play as Gordon, call it "Half-Life: Freeman" and you wouldn't be making the same argument about the missing 3. Just like how if they made a mobile-only strategy game and called it Half-Life 3, people would completely reject the idea. It's all fan headcanon. I realise it's gonna be an uphill battle against die hard Half-Life fans, but let it go. Alyx is not the sequel you wanted, but it's the sequel you got. This idea that
13 years later the "true sequel is still yet to come" is nonsense. Alyx is the first full original Valve script since Portal 2 almost a decade ago and it's the closest you're going to get.
Feel free to quote me on this post when they announce Half-Life 3 in 2031.