I don't see how this follows. Your initial implementation of your idea was not very effective. You learned that you needed faster hardware. You implicitly discovered that you wanted something different than you initially thought you wanted. (In any kind of construction, including software architecture, the change orders that result from learning what is wrong with the design while building the design are both expensive and important.)

I suggested one way of solving the problem: with slightly more expensive hardware and a shift to already-available software that solves your problem, which I trust (1) because it is all free software so everybody can see what it does by reading it, which you can't do with the code running on the other side of someone's service, as you remark; and (2) because the project making it is run by me and my comrades, and we trust one another to follow the rules of transparency and respecting users' rights, subject always to complete ongoing inspection.

But we could also solve your problem at no hardware cost and using only free software. We could use the storage that Columbia gives your for free on your cunix account, and we could use tools like "tomb" to create an encrypted container on that account and tools like sshfs to access that container over a secure connection from your laptop anywhere. The effect would be to give you a folder contianing all your files organized however you want them that would look like Google Drive does, but which would be secure at rest and secure in flight and operated by you without any hardware or any cost. The space is limited by what Columbia gives you, but we could do the same thing using an Amazon S3 bucket---which you wouldn't have to trust Amazon about because it is encrypted with keys they don't have---and s3fs or the equivalent.

In other words, it's good to have some amount of knowledge, and fairly illogical to say that you wanted to find out whether something was possible to learn, but because you weren't successful in learning it the first time you tried learning is impossible and everyone should know that your experiment proves they should give up.

Why does the answer to this question, which I taught and which we discussed, not make an appearance here? When one uses free software one does not have to "trust" people who tell you what software does: one can read it. And if you don't or can't read it, you can listen to the conversation among the millions of people who do make, use, improve, and distribute free software, from companies like Oracle and Red Hat in the S&P 500 to the technical workers in your social circle. They teach people how to understand how it works, and are constantly checking on its reliability. What you are posing as a recursive difficulty in knowing whom to trust is actually a full technical ecology of trust management that answers your objection so basically and so strongly that most of the world's corporate IT already depends on it.