We've already seen bigger sites - like Threads, for instance - try to integrate into the overall ecosystem.
People complain that the mainstream sites are relatively closed ecosystems, but they also complain when those sites try to be more open ¯\_(ツ)_/¯
ActivityPub is the protocol though. Mastodon is an implementation of the protocol.
Bluesky is (in theory) federated, but I think you can't run your own server yet. We'll see if they keep their promise.
Its protocol has some improvements over ActivityPub, for example you can use a domain name you own as your username even if you're not hosting your own instance, and your user identity is portable in that case - you can move to a different instance but keep the same username.
I'll be sure to buy myself something nice for Christmas.
Upstream is usually still your ISP's network for a while longer. The splitter box goes into some other equipment owned by your ISP.
Well it isn't shared before the upstream server, that's what FTTH is.
FTTH just means that there's fiber going into your house.
Most residential fiber internet connections use a technology called PON (GPON for gigabit or XGS-PON for 10Gbps). My understanding is that the fiber from your house goes into a splitter box in the street, which takes fiber connections from many customers (usually either 32 or 64 customers) and multiplexes them into a single fiber by either using different wavelengths of light or by time multiplexing. Upstream from this, bandwidth is shared.
The bandwidth is still shared... It'd be prohibitively expensive to have dedicated bandwidth just for your connection, and most customers don't need anywhere near that. Unlimited, dedicated 1Gbps is around 320TB of data per month.
A business-grade connection has fewer people sharing it, but it's still shared. The only fully-dedicated connections are enterprise-grade connections (like in a data center), and even then it's an upgrade that costs quite a bit. :)
You're right - upstream connections are usually fiber. In fact there's a name for this type of network: HFC (hybrid fiber + coax)
The 2Gbps symmetric though Comcast is still cable. In theory, DOCSIS 4.0 supports up to 10Gbps down and 6Gbps up over cable, although real-world speeds are always lower than theoretical speeds.
You share bandwidth with your neighbours regardless of whether it's coax or fiber. A common contention ratio for residential connections is between 40:1 and 50:1, meaning the bandwidth is shared between 40 and 50 people (i.e. 1Gbps of upstream bandwidth per 40-50 people with a 1Gbps connection). This is usually fine as it's very unlikely that every customer will be using the full bandwidth at the same time. Residential usage is usually very spiky with only brief periods of high speed usage.
Breville is such a good brand. Not very well known in the USA since they're an Australian brand. Kinda expensive, but very high quality.
Comcast is still using Coax instead of Fiber Optic and desperately trying to convince people that somehow, someway coax can be just as good.
Comcast are starting to offer 2Gbps symmetric (same speed up and down) via DOCSIS 4.0 in some areas.
Not 100% sure but I don't think anything would stop either a fork or a new app that uses the same protocol.