Hopefully change becomes easier with FOSS options becoming more capable.

• LibreOffice can handle most common document formats for business, I think the main thing they're missing is a MS Projects alternative.
• NextCloud can handle cloud syncing.
• There's plenty of email managers like Thunderbird, and there's already a wide variety of email providers and a large company can afford to manage email themselves.
• Matrix and XMPP are developed enough that they can easily replace Teams and Slack

And the best thing (for businesses) about all of these options are that there's no licensing costs. There's already some companies switching to FOSS tech stacks, and so long as they're successful the trend could spread. Even more so if Europe succeeds at breaking away from US tech companies, since their adoption would mean even more funding for FOSS development