There seem to be two views of crypto. One is purely treating it as an investment, but the other is about what problems it solves. Bitcoin is lacking in the latter (slow, expensive, non-scalable) and other coins improve on it in various ways. To be viable a coin needs to get used enough to become essential to some set of people. Then it gains value. There will be no one coin that does it all for everyone. So we cannot get by with just Bitcoin, assuming crypto has a future. The whole crypto space is still small compared to the bigger financial systems and it is moving fast. At 10 years in this still counts as early days.
Saying Bitcoin is all we need is like saying we can get by forever with VHS.
Of course I'd love to see Steem succeed, but it has to expand to serve many more people. It has that potential, but I don't know how it can get there.