Uhm, what? How did you come up with the conclusion about bitcoin being a scam just with that statement?
Also, take note that the biggest wallets that contain the biggest number of bitcoins doesn't automatically mean 1000 people own 85% of all bitcoin. Take note that exchanges are a part of that 1000(assuming this statistic is actually true), hence, it doesn't mean that 1000 people own 85% of BTC. Take note that the top exchanges has A LOT of users. We're talking multi-millions here. Binance itself was gaining a few million of users per week just sometime last year. Think about it.
1000 addresses hold 85% of all BTC =/=(not equal to) 1000 people hold 85% of all BTC
This is true about exchanges, but the exchange addresses are just a few and like you said, these addresses refer to thousands of customers. So if we exclude a dozen addresses (or twenty), we are left with, let's say, 990/980 addresses.
It could also be that, apart from the dozen or so addresses related to Exchanges, the other 990 don't belong to 990 different people, but maybe much less. There could also be some big whale who owns maybe 10 or 20 of the biggest addresses that we see in the first thousand. We don't know in reality, because every address is of course anonymous. Maybe (just a supposition) one hundred real people own the majority of bitcoins in the first thousand addresses, apart from the exchange ones.
Here a look of the bitcoin rich list address, where is pointed out the addresses which are owned by exchanges:
https://bitinfocharts.com/top-100-richest-bitcoin-addresses.htmlIt is addresses that hadn't done anything for the last two years. That is not exchanges. That is whales seing off. It states there is 40% more BTC in circulation since they started selling.