The idea of re-implementing all those SaaS web apps as Linux apps is completely absurd and doesn’t benefit the end user.

Not all, only those that don't work in Linux for some inexplainable reason and whose developers no longer want government contract money. I think you'll find that that number is basically zero.

So it’s okay to have proprietary software as long as it is running on an open source operating system?

If you want, but why would you want that when there are as good and often better FOSS alternatives. With FOSS stuff you can have your cake and use any kind of plate you want to eat it from.

Is there a “better” alternative to an Office 365 subscription that comes with Word, Excel, PowerPoint, One Drive online storage, hosted email and each user csn use the same set of software between Macs, Windows, Web, Android, iPhones, iPads, etc?

A business can get that at retail for $160/year. A student can buy that for $79.00/4 years.

Those are retail prices. I can guarantee you that large organizations aren’t paying retail.

And don’t overlook the online component and the governance and the SSO. I know plenty of MS shops that use MS’s hosted SSO solution to log in to AWS.

It amazes me how little HN understands about the needs of large enterprises.

Heck I work for one of the Big 5 tech companies (FAANG - Netflix + Microsoft) and it isn’t MS and we all have Microsoft licenses.

What does a student need the MS Office package for in a school context?