If someone was willing to invest into building and maintaining infrastructure there would be no need for this concept, but that’s a political issue. The idea of this concept is do make the best of what you have.

How would traffic pass each other? You would be stuck with the same issue as normal trains.

Better by what standard? They aren’t the most used apps just for not being foss.

Hmm the prices on eBay really don’t seem that good to me in comparison to newer generations. I guess the power consumption will eat up any savings pretty quickly. Though this might differ for whole sets.

If you rent a VPS that might get you kicked, so check your terms first.

Imho that’s a horrible idea. A large part of content on the instance I’m on has become bots just reposting news articles without any own contribution, no discussion, nothing.

Of course it’s not about centralisation per se, but the problems that a centralised platform does not have to deal with.