This is interesting perspective.
If I'm interpreting what your saying correctly, this becomes an alternation of the "Traveling Salesman Problem" - where people are the nodes, sending information is the destination, and medium of communication is the weight. The goal being finding the shortest path for two-way communication (go to destination and return).
If this is the case, "tyranny of majority" is indeed a very difficult problem to solve. This phenomena causes the weights of the graph to become change based on the number of surrounding nodes. Higher when less nodes (i.e Lemmy) and lower when more nodes (i.e Reddit).
To go even further, companies are manipulating their weights (creating closed ecosystems, etc) to make is so two-way communication is only viable within their bubble (think an edge of infinite weight). And it would also mean that it truly is unreasonable to expect laymen to "memorize the graph" (know a forum for everything) - it indeed would be just easier to know a subsection (i.e Reddit, Facebook, etc)
I'm just spitballing here, but a lot to interpret if true.