My impression was always that Bitcoin matters mostly because for many it is being considered a "bridge" between crypto and FIAT. I wonder if BTC will ever lose it's role as a "king of all cryptos".

That's correct. BTC is mainly flourishing because many still see it as the measure of all crypto value. Libra cannot stand because it can't be trusted as much as BTC is.

As for your prophesy I see it being fulfilled somewhere around 2021. We'll see what happens. Cheers!