The point is, that our local government funding perhaps should PAY to bring software improvements, because FOSS will be maintainable by which ever IT contractor comes along after deployment.
Buying Micro$oft for decades, has just bought more "lock in". A solution is (by definition) whatever combination of hardware/software does the job. I bet you have seen the contracts that state "Must be compatible with Micro$oft tools", just to exclude opensource alternatives. Expecting a drop in replacement was clearly part of the intent, but does everyone FORGET how terrible M$ products were? (I cannot comment on modern versions after 2007).
I have 6 accounts with different institutions managed using Thunderbird, PGP and GoogleChat and many other bells and whistles to manage spam . The solution is to have standards based servers so the clients DON'T MATTER.
Large scale is much simpler when everyone runs the same version...and with Linux distributions this is *definitely* more straightforward than M$ if only because of the licensing/patch circus.
The long term vision is where our taxes don't prop up corporate share prices but implement solutions that work for everyone. The only way that is going to happen is FOSS (or contracts for software export), so there is no expectation by $CORP that they get to stay the provider for 20 years.