They're the same as other wallets that have built in exchange and it's convenient for most of their users to use their exchange instead of transferring it specially if it's Ethereum to avoid higher fees.
Has anyone gone through their KYC? Will you actually try this, on what basis?
I haven't and I don't think that I'll get on them passing KYC. But if it's about diversification, it's a good company though knowing that they're very popular as a wallet but instead of investing on them, I'd rather hold bitcoin.