This has been their website for experiments for years. Its for people to try out and not for the entire world to use as yet. It has had a lot of fun stuff over the years
(This is also my personal nomination for the oft-asked "when did Google stop being unique and cool?").
A long time ago they even started a trend - 20% time for personal projects, that was an act of exploration, but now they lost their curiosity and playfulness.
Okay, sure, it made sense to shut it down, but to me it would make sense to do a new one today for the aforementioned reasons (use cases).
(But of course somehow most of Alphabet is still tragicomically bad at B2C, and now YT also seems to be going down the drain with the overemphasis on shorts.)
Maybe it’s time to up their game.