> And how do you do that? You think EU companies will stop buying Office 365 subscriptions to reduce their dependency on the US?

Most workers in most companies probably don't really need an entire Office suite. It is just they use Outlook and from time to time open a Word document that could've been a PDF or HTML form if they had better processes. For the same reason, most people don't really need to use Windows. However people use Windows, because a lot of "professional" software only ships for it and nobody is going to rewrite an app that the enterprise uses for the last 20 years to prevent the use of Windows or some of its particular version. If it was that easy, why would Windows XP or Windows 7 be still so wide-spread?

> Companies buy Office 365 subscriptions so they can focus on their main business and don't want to think about their office solution and want something that JustWorks which is already compatible with what everyone else uses.

The problem is, many programs in the Office suite don't just work. Being an admin in a larger organization you will face a broken .pst file basically every week. 10+ GB of emails seems to be a problem also considering the search speed etc. The level of engineering incompetence behind Outlook is high. It even has special conditional HTML just so Outlook renders some things correctly, because Microsoft is long term incapable of implementing a web engine to a degree that they had to adopt and adapt a competitors product (Chromium).
Similarly for Excel. Most things that are in Excel shouldn't be and instead should be a table + some app in a database or a form + database backend. We have seen that during COVID-19, when essential health data was messed up because of wrong use of Excel but also because Excel just wasn't the right tool for the job frankly. We have been renaming genes or whatever, because Excel has insufficient auto-formatting algorithms and people have to learn how to prevent this - which is proof it doesn't "Just Work" for people.

> They have a business to run and money to makes, so spending extra time and effort on alternative office solutions with various degrees of compatibility, just to fight a virtual trade war, will slow then down significantly from their main business goal.

Most things in most companies should be formalized in digital forms backed by some processing backend. Most companies just are not very good at management therefore they fill these gaps by using more flexible tools where everybody can unfold their creativity generally making a mess making any kind of formalization much harder later on.

No question there are also jobs where you need that flexibility, e.g. where you get data from people precisely in these formats and are expected to produce output in these formats for them too. Because people are generally opposed to change and don't want to learn, if they can avoid it. Much better tools are available for so many activities yet people usually opt for a product out of the Office suite.

> Why do you think Google uses SAP instead of rolling out their own solution? You think they don't have the technical know-how, or is it because it's not worth the effort and better use what everyone else is already using and focus your resoruces on what really matters?

Because promotions are easier to get if you work on a product that makes money for the company (such as search + ads) or is a big cost center and a needed pre-condition for the business (such as the cloud infrastructure) and you can implement changes that safe the company a lot of money.
However, don't underestimate how much SAP was customized for Google. It could be that SAP is just the core of a much bigger system.