They also highlight an large inflows to exchanges primarily serving North America:

North American exchanges were losing Bitcoin on net in the early part of the 2017 bull run, and became a net receiver as price began to peak. This time around though, North American exchanges have been in the green throughout, with inflows ramping up to higher levels than at any point in the 2017 run in the last few months.
I find this intriguing.
This could be a byproduct of the increasingly rigid regulatory atmosphere. The FATF travel rule, exchanges segregating between their US/EU platforms and the rest of the world, the UK banning crypto derivatives, Bitmex being charged, etc. Less inflows and volume on opaque and unregulated exchanges, and more inflows in the opposite direction.
This is exactly what CME executives were getting at when they said they would "tame" Bitcoin a few years back. It's also exactly what the SEC wanted to see before they'd be willing to approve an ETF.