All the Ethereum is flowing in to decentralized exchanges and liquidity pools... 2020 was big step for decentralized exchanges and wrapped tokens, and I'm confident the trend is going to continue as a lot of new cryptocurrencies had troubles listing to exchanges due to a few hacks and some exchanges having strict listing requirements...
After Ethereum switches to PoS, the number of wrapped tokens will skyrocket as the expenses running cryptocurrency bridges will sink like Titanic.
Yep, I am sure that is a big part of it. Also with the upcoming FinCEN rule changes, it may be people getting their crypto off exchanges while they still can without having to report where it's going.
Like I said before, moving too many coins to own wallet drops the value of the coin, so most smarter people won't do it unless they have enough to be able to stake when the PoS switch happens. It makes more sense to buy ERC20 tokens instead...