Btw, an interesting aspect to #Meta's entry that I haven't yet seen mentioned..
It's not just Meta to worry about. When they launch and the press release proudly mentions their 'open standards' approach, then this will be trigger for an unprecedented influx of businesses adding #ActivityPub support and joining the #Fediverse.
Meta will basically indicate to the market: this technology ecosystem is "good to go", economically viable and we're in it. #Metaverse-like hype ensues.