If your insurance denies coverage when your DIY repair causes a loss, I think the advantage is overstated. Part of hiring a pro is the knowledge and tools, part of it is shifting the liability to someone insured and bonded.

I know enough building sciences to do most repairs or renovations myself. I still pay for a professional when I don’t want the liability risk (plumbing or electrical in a large multifamily property, for example). A few hundred dollars is always cheaper than my property insurance deductible, or the entire loss of coverage is denied (and property insurers are denying roughly half of annual claims).