I agree with your post; it's partly the reason I got involved with cryptocurrencies in the first place (that and I'm just a general geek and hated seeing so many cpu cycles going unused in my home systems :). Steem is a great example of what the Web 3.0 could look like, so I've committed extra cycles to it...
It may be a case where steem might serve better as a store of value instead of a medium for exchange (though I don't believe any crypto has reached that goal in a universal sense). Bitcoin has too many limits in it's transaction capacity to really be an effective medium for exchange (though it is used that way in a few places still today), but it does work as a store of value (it would be better at that if its value was more stable, of course). There are many projects competing to be the universal exchange token (but who has time to follow them all!).
The advantage I see with using different projects for different purposes is that it is hard for one token to be all things for all people, especially if you don't have a well funded full time development and marketing staff! Right now steem has a long way to go before there is some steem in everyone's crypto wallet, but it does have a great head start as a place to grow your holdings (and store your value). Nonetheless, it is headed in the right direction...
I am hoping that SMTs will solve this problem for Steem for content needs, as they can be configured in multiple ways. When it comes to various use cases, there is space for many, many tokens and chains, though some will be more utilized than others. I see it kind of like audience tickets for events. Some might have mass appeal like NFL, others are like the ballet. all can have value as long as there are buyers of tickets.