It sounds like you are doing amazing things from a security perspective, but that those are not included in your report, which means that your customers are missing out on. As you mentioned, sure you can put it in a white paper, but who is to say that you are actually doing it? That's the point of the SOC 2 report.
My hunch on this comes from the fact that you mentioned that SOC 2 comes from answering a giant spreadsheet from your auditors. It doesn't really, however that is how a lot of auditing firms get their clients to become compliant with SOC 2. They need something, and a spreadsheet is a good place to start.
You're right, some businesses won't need AV, or Background checks, but in your case if it makes sense to have a control that mentions "The company only leverages memory-safe languages", you should be able to, and even explain it further in your Section 3. The key is to design controls that address the SOC 2 criteria but also are 100% reflective of how you are operating your business. It sounds to me like you got to SOC 2, but that you could get a lot more out of it. This is unfortunately super common.
Source: I help SaaS companies with SOC 2 and I have been for 7 years now. Currently helping companies in unusual spaces such as crypto exchanges and making sure that all the amazing work they put in security is reflected in their report. I'd love to chat more in depth if you are interested, I am very passionate about this and I've worked with a lot of companies you probably use one way or another in your stack, or that are in a similar space as yours. Don't hesitate to reach out and good luck!