Yep exactly.
Another worry of these centralized services is that they could deny users access to private keys, as was just announced today in Russia: https://en.bitnovosti.com/2018/05/22/russian-state-duma-adopted-the-draft-law-on-regulation-of-cryptocurrency-transactions/
This would essentially mean you could ONLY use crypto via 3rd parties, which again, would defeat crypto’s entire purpose.