You don't have to trust anyone with your Bitcoin. You can store your wallet locally, you can keep a paper wallet, you can keep a wallet on your phone, back it up, encrypt it, do whatever you feel is necessary to secure it. You can even get a hardware wallet if you want extra security. There is no need to store your coins in an online exchange at all.
There's also numerous uses for Bitcoin besides the black market. If you're into video games or movies, you could sell a bunch of your old games on OpenBazaar with no fees, then walk into any branch of CeX and buy some new ones with Bitcoin.
There are many legitimate uses for Bitcoin and many ways to store them without trusting third-party cloud services.