It's an article written without taking into consideration that using USD block value data as metric isn't the right way to move forward in this case.
Just because Bitcoin's network has processed like $900 billion in value doesn't mean everything is related to OTC trades.
Some interesting stats;
Block 500002 (2017-12-18) is the highest ever USD block value measured = $3.55 billion.
Block 506462 (2018-01-28) is this year's highest USD block value measured = $1.91 billion.
Block 394736 (2016-01-24) has the highest ever BTC output value measured = 6.5 million BTC.
Block 500546 (2017-22-12) has the highest ever USD block fee measured = $240,800 (lucky miners).