The technology must be able to scale. We had an attempt at mass adoption late last year, but once bitcoin transactions cost $100 to send a single transaction because the blocks were full, everyone knew it couldn't go any farther. LN is still possibly years away from being stable. BCH decided to increase block sizes and is doing what Satoshi Nakamoto said to do in the early days if block sizes fill up. Of course this means increased latency, centralized mining, but we already have both in bitcoin anyway.

I think mass adoption can happen sooner than 2028, but only if / when the scaling issue is resolved. Because some cryptos have already solved the scaling issue, I think it more likely that DPoS coins will take the lead in the next couple of years. This would be Dan Larimer's projects, EOS, Bitshares and Steem. If bitcoin can solve the scaling issue it has a chance to stay on top, but it had better do it soon. One of the features helping bitcoin is the fact that it's a significantly different use case than EOS, therefore there is plenty of room for both currencies.