Ask HN: Do you regret building your own software as a non-technical company?

I've already seen several internal tools becoming a burden for the company that has created them. Development is costly and the resulting product is often buggy, unreliable and demands constant work and attention.

Is that a common thing? Is it a bad idea by default for a non-technical non-SaaS company to hire developers and build anything custom?

I would say this is even common in technical companies. Many tech companies suffer from NIH syndrome, and needlessly re-invent things that already exist elsewhere, or are not part of their core business. I've witnessed it many times. I would say this is especially common when the company has too much cash on hand and can squander it...