It’s a fair assumption the OP is not one of them given the website we’re on, and their stated opposition to handing custody of their funds to others.

Also, plenty of retail “investors” seem to be moving away from the exchanges:

https://www.reuters.com/technology/cryptoverse-bitcoin-inves...

Don't know about crypto, but for Bitcoin:

~11% of the Bitcoin supply is held by exchanges, and it decreases on average by 2,500 BTC per day or ~5% per year (over the last 3 years).

That just means they are not stored there as often, not that the exchanges are where most bitcoin related transactions happen