I think the key distinction is that there is a well-established infrastructure around software, such that the average SaaS founder (even 10 years ago) is/was not doing fundamentally new things with computers. If they were, they would probably need to understand computer science well. Take any moonshot ML company- they need quite deep technical depth and usually have a founder that has spent time in academia.

We are still at a point in Biotech where companies have to do fundamentally new things with their tech to succeed. If you were starting a company that applies CRISPR to X genetic disease, you might not need a Ph D. to start the company, because you can apply existing technology to solve that problem. But that begs the question: Why has no one else done it yet?

At the end of the day, you need a unique insight to start a large company. That means experience with either the problem space or the technology space is helpful. Not discouraging OP either, if you have a vision for what the future should look like, and can acquire talent/capital... anyone can start a massive company. So OP should try to acquire that vision.