Check out the complains on reddit regarding blocking of funds of different members pending KYC verification.
If you have been using them minus KYC, then you are still lucky, I doesn't mean they won't hesitate to ask for KYC verification in future.
They even talk about KYC here - https://changelly.com/aml-kyc
Dexes like Pancakeswap are very limited. They may not favour cross-chain swaps like tradition instant swap exchanges do. For example I can not use pancakeswap to exchange my Monero for Bitcoin (I mean the real Bitcoin, not the tokenized BEP20 crap )
KYC sucks real bad. It defeats the whole purpose of crypto/Blockchain tech. ShapeShift was popular in its early days because it didn't require traders to verify their ID. You'd just exchange from one crypto to another without any KYC whatsoever. I fail to see why governments want to regulate a crypto-only exchange, when crypto is out of their jurisdiction. KYC/AML would only apply if there was a trade between Fiat and crypto or vice versa. But that's not the case these days, greatly undermining crypto/Blockchain tech's growth in the mainstream world.
At least, there are many other alternatives to both ShapeShift and Changelly on the market. And if instant exchanges aren't enough, there's always the choice of atomic swaps. Crypto/Blockchain tech's decentralization allows for greater freedom even when regulations come into play. It seems to me that anti-KYC exchanges will be here to stay as governments will be unable to enforce regulations towards the entire crypto/Blockchain space. ShapeShift may ultimately go out of business, as people flock to other alternatives that are free of KYC. Just my thoughts