Why? Lack of on-premise and offline based software. Consequently, the innovation today is almost exclusive to SaaS based products. On-premise and offline client software is just becoming an optional expensive side-product of every SaaS product.
But it's a pretty logical step forward. As for the value, SaaS eliminates administration, installation, hardware, technical support and security hastle and majorly cuts the costs for a client company. As for the price, we always praise the always blooming software industry, successful startups, awesome jobs with so many perks and benefits, but someone has to pay for it. I think people don't consider that software is just getting very valuable and too expensive to make and it just makes more sense for companies to rent it then to own it forever.
And now they have to deal with cloud leaks of sensitive data that they no longer control and various SOC2/ISO "certifications" increasingly look like security theater and a "feel good" measure because they don't guarantee anything.