On a town square drunk people also say stupid things, so yes, perhaps Twitter is the modern town square.

As for a wise investment, it's not. A website can't result in a free speech platform, because it's a centralized technology. The WWW is centralized in many ways. The core internet infrastructure could be distributed, but many parts aren't. 99.999% of consumers don't run their own AS, which also just depends on a centralized allocation.

A true distributed internet would mean everyone has like twenty independent service providers and no amount of government intervention would be able to kill it. Instead, we see that countries routinely block the entire Internet when it's convenient for them (like in Russia).