Coinmarketcap never was not accurate, I heard news about fake exchanges volumes there 2-3 years ago.

And yes - Coingecko may be even better, with more information and more exchanges.

CoinGecko had devised an acceptable method (at the time) do distinguish between wash trading and fake volume computing it with visited to the exchanges websites.
Now all these "fake exchanges" and some in the top 20 have figured ways around it with 0 fee accounts.
I dont doubt even some exchanges we think are all legit are doing the same.
There are still a few ways to determine which are fake and which are real.
You can watch the trades go by in the spread and thrown up in a split second.

MikeMike

There are about 20-40+ Chinese and other exchanges that are now gaming the CoinGecko system of normalized volume.
Some even offer accounts with no fees to pump up their "real" volume.
Seeing an exchange come out with their new release adding 60 languages an increase their volume from 400-600k to 6million in a week is ludicrous.