When you use cloud services, you are storing your data on other people's hard drives. The moment you put your data within a cloud service, that data is no longer under your control. You don't know who will access that data. Secrecy is lost.
Instead of using services like Gmail you may opt to setup some virtual private server and run your own email server, but that doesn't change a thing. The cloud provider controls the hardware, they have access to every bit you store on their platform.
If you encrypt the hard drive of your VPS you need to enter the encryption password every time you reboot your VPS. And how can you remotely type in the password? On the VPS console, a piece of software written by and under control of your cloud provider. They can snoop on every character you enter.
This may all sound far-fetched but it's about the principle of how things work. If you store unencrypted data on hardware that is not owned by you and under your physical control, that data cannot be trusted to stay secret.
If you care about the secrecy of your data, you should never store it with a cloud provider or any other third party.
I believe that the price you have to pay for any decent secrecy of your data is to run your own physical server. This is way more expensive in terms of time and money than using a cloud service, so it's up to you if it's worth it.
Although your own server will probably prevent your data being souped up with dragnet government surveillance, it will still be difficult if not impossible to protect you from a targeted investigation by a government agency.
A government agency can obtain physical access to your server and physical access is often the deathblow to any secrecy / security. Even if you implement encryption in the right manner, you are only decreasing the chance of their success of accessing your data, you are not eliminating their chances.
But there may still be a small benefit. If a government agency requires a cloud service provider to hand over your data, they can do so without your knowledge. A gag order will prohibit the cloud provider from informing you. However, if the servers are your own and are located within a building you own, either privately or as a company, you are at least aware of what's happening. That may or may not be relevant to you, that's up to you to decide.