It goes to show how much polish and care Valve going into for their games, and I'm going to guess its part of a reason why we haven't seen much content from them in the past decade. Iirc they cancelled so many HL titles after HL2 Ep 2 due to unhappy results - https://www.ign.com/articles/valve-explains-why-half-life-2-episode-3-was-never-made.
Imo they are like the Nintendo of the PC space where each release you know you get a product made with care, and has high level of quality assurance.
If Valve decides to make another L4D that would be pretty cool. I'd lose my shit if they made a mainline non VR Half Life game.