Every project has a different goal and industry, you can not expect all of them to make it as a global payment system. Let's say a pharmaceutical token based project, the project is limited only to buy the medicine and in this area. Does that mean, this token is bad? no, because this is what they are aiming for.
Proof of Stake is a consensus, the use case depends on the project itself. Why people love it?
It is because it is cost effective compared to POW in running the blockchain, you can get a passive income from holding it, the majority POS project are faster in term of transaction speed compared to POW.
I agree. Every project do really have different goals and usage for the society. It does not intend that a token from different projects must cater all around use because the token is design for a specific usage. The aim of every project is to promote solutions for societal problems in use of the modern technology which includes the use of blockchain technology in short cryptocurrency tokens. Every tokens have their own real usage which is unique based on the specifications designed by the project creator. So we must not always expect that all tokens can be used beyond their designation. It is because of their main usage why people uses it not just basically by their price due to the fact that they do possess their own purpose of existence.