I would make few points here.
The type of the application often dictates how it has to be delivered.
For example, I make SumatraPDF, a pdf reader for Windows. It wouldn't work very well as a web app so it wouldn't be a good SaaS product.
If I were, for example, write an app that combines 2 pdfs into one, web-based UI + backed running on a server would be good enough and easier for me to implement that a native Windows app.
Pricing/delivery strategy is rarely what makes or breaks the business.
Picking the best pricing strategy is an optimization for the case where you already have a product that sells. JetBrains recently switched pricing for their desktop software from one-time fee to a subscription model. It was probably a good business decision for them but they built their business for 15 years using the traditional pay-once scheme.
The hard part is building software that people want to use and pay for.
A business model usually just falls out from the kind of software it is. If it's a web app that is continuously used, subscription is an obvious choice. If it's a web app that is used once in a while (but for a high-value task), then charge for usage. If it's a book, then one time fee is pretty much the only option people would accept etc.