$80 billion is not just a mere figure, athough bitcoin may be experiencing some challenges now due to some fundamentals and FUDs coming from different sources once those challenges is surmounted the price will surge upward because bitcoin is more popular than ethereum thus it's market capitalization will increase too.
If the bitcoin cannot scale properly to accommodate the increased trade, people will use the Ethereum or Bitcoin Cash instead. So it is possible the latter two can overtake bitcoin.