LibreSaaS is Free/Libre Open Source Software maintained on a server that people can access. FLOSS as a service.
LibreSaaS can lower the barrier to using Free Software.
LibreSaaS provides a powerful business model for developing Free Software: Bundling the hosting and the software development costs together.
And LibreSaaS solves the problem that while it is a smarter use of resources to have specialized talent and economies of scale to run software and hardware infrastructure, but doing so typically relies on some commercial, for-profit entity, which, at virtually any time, might change its direction in a negative way.
LibreSaaS is potential freedom.
This makes it both a business and a moral imperative.
No Lock-In
The importance of a full no-lock-in stack.
If any element of software or services you rely on is proprietary, you are in a position of facing extortionate prices, permanent service shutdowns, or inflexibility to adapt your tools to your needs.
For all the reasons Free Software generally is a moral imperative, but with the crucial flexibility of not having to run it on one's own computer, people and institutions need LibreSaaS.
The cloud is indeed only other people's computers, but that 'only' can be a crucial distinction between having access to the power of some software and not having access to it. Ideally, LibreSaaS is provided by platform cooperatives so that the Free Software code is in fact being run on our own computers after all— computers for which we share ownership.