The Document Foundation does not provide professional support services for LibreOffice. It does, however, develop and maintain a certification system for professionals of various kinds who deliver and sell services around LibreOffice.

That's a LOT different than the support you can get from Office. Enterprise contracts usually come with guaranteed uptime, 24/7 immediate L3 support, custom hotfixes for specific workflow issues, and much more.

I get that it's expensive, most people don't need that, and there should be better options. Unfortunately, there quite often isn't. The difference between Office and the second best of a huge margin.

On top of that, the integration costs can be massive as all your workflows are built for Office products. At the least, the companies need to find a way to replace all your macros, addins, and queries.

Support is a service, so is deploying and maintaining software.

Also the list is a great case in point. If you want them to speak German, looking at the names, you end up with three trainers and a single migration expert. To be fair there seem to be a lot of German speaking developers, but they tend to hate working in support. Just imagine somebody is sick or on vacation.

Also LibreOffice is a large open source project. For smaller ones it is much worse.

Yeah, that's the point. Microsoft Office is a service with support and downtime guarantees.