It depends. For example first household workstation was available in 1974 and when it become mainstream? Around 90's. Also during some phases there is slower adoption, during another faster. Yes, adoption is still very low. Your example with iPhone is valid for hardware but not for software, Bitcoin is evolving in time and when SigWit is enabled, it will move forward a lot. So it might never be obsolete. Of course there will be some more agile projects as Steem and another. Bitcoin might have only 10% market share in few years. But it's good we have so many crypto projects, it will move all the sector forward a lot.

Bitcon, same as Steem has actually lot of demand factors but not for everyone, as Steem is also not useful for everyone. Currently Bitcoin has lower inflation that Steem, therefore is better to store value, with Bitcoin you can directly utilize many interesting services like purse.io, gyft to buy things for better price, utilize jobs services, etc., with Bitcoin you can invest and fund thousands of projects, with Bitcoin you can easily access any alt market. So although it has no integrated platform inside, there are multiple useful services and utilizations primarily built around Bitcoin.

You are right, old world with most of its elites doesn't like crypto and Bitcoin because it's disrupting world system which was and still is source of their profit and power. They tried FUD and repression first, during next phase they might try to buy it all and manipulate (like gold and silver), who knows. But it will be hard for them. Once it's manipulated, community can build another project that is not owned by them and move on there.