Why should those exchanges collect our personal information? Do you think KYC is necessary?
It depends a lot by the exchange's profile.
If the exchange works with fiat, the legislation asks it to collect KYC info. If it doesn't it's an illegal business.
If the exchange doesn't work with fiat, I think that it can work without KYC in many countries (?).
Many point to Binance as example. I think that they've somehow avoided the law by using 3rd party operators (afaik) for their fiat operations. It's a solution, but I don't know how long it'll work. Binance also asks for KYC if people want their debit cards or big transfers.
The real problem is that there are so many exchanges (and other businesses!) asking for KYC although they can live without it (and some "businesses" only exist as long as they can get KYC details they can sell!).
Another real problem is that many people give out their KYC without thinking much, sometimes only to get a few dollars (or cents!) worth of tokens. Or enroll to all (big or small) exchanges (with KYC) without thinking twice. At some point one will be sloppy (or with bad intentions) and problems will happen.