SaaS is good because it gives you a constant income stream, which matches the constant development of your product.

For the user however, it means lock-in and their data being held ransom.

A good SaaS manages to remedy the downsides to enable the upsides to shine, i.e. data export, open formats, open core, open source + hosting business, ... and hopefully more diverse and better ideas to cover more markets, use and business cases.