I thought for sure it would take until the end of 2018 but it looks like this summer ethereum might pass it up. With the turmoil around BTC potential splitting, it might be very soon. IMO this is healthy, we will always value bitcoin for being the one that started it all, but it's time for a more dynamic and adaptable currency to take the lead.
My previous thinking was similar to yours, but I don't think so now, bitcoin technology, blockchain has been recognized by many countries
As long as the blockchain does not disappear, bitcoin will always be first