We're building the business, i.e. setting the foundations we expect to stand on for decades to come. Enterprise license that might be possible to extend into the medium term isn't good enough for our long term commitments and the time to adapt to an alternative family of operating systems is now.

As for stability, if you learned GUI Ubuntu twenty years ago you'll be right at home in contemporary Debian systems, while someone hopping from XP or Server 2000 into 10 or 11 would be quite confused for quite some time. Xenial (2016), Bionic (2018) and Fossa (2020) will likely get twenty years of security updates each, into the beginning of the 2030s.

I think something similar holds for the SoftMaker office suite. If you learned TextMaker twenty years ago I believe you'll be less annoyed by their 2024 release than if you learned Office 2003 and get dropped into the 365 style applications. Personally I'd use something else entirely, likely doing a roundtrip through LaTeX or straight PostScript under the hood, but it will be interesting to evaluate some MICROS~1 Office alternatives in my organisation and see what, if anything, sticks.