The chasm is enormous, but Calc doesn't need to implement 100% of Excel's functionality when most people - even business/power users - don't use all of its features.

What major commonly used features do you reckon Excel has that hasn't been implemented in LO Calc yet, that would be a deal-breaker for most businesses?

To my knowledge, Calc has implemented most of Excel's formulae (well over 500 in total count), so at least for typical spreadsheet functionality you wouldn't missing anything.

The biggest limitation I can think of is the limited support for VBA, but Microsoft have already announced VBA's deprecation[1], so no one should be relying on it even in MS World.

And whilst LO's own Basic scripting is... basic, it also supports rich scripting and full automation via Python and Javascript. It even has a full-fledged SDK for developing addins/extensions using a high-level language like C++/Java etc[2], so businesses who're dependent on some random proprietary excel COM addin or something could invest in development effort to port it over.

Heck, if businesses are so inclined, they could modify the LO source itself and build a custom version to add the features they want - that's the beauty of FOSS.

[1] https://devblogs.microsoft.com/microsoft365dev/how-to-prepar...

[2] https://api.libreoffice.org/

You don't use all it's feature, but if you need part of the 10% of features that Calc doesn't support, then your in a world of hurt.

When Calc gets the other 90% of the features Excel has, you also need to contend with word, Outlook, Visio and all the rest that Libre Office has a 0% solution for.

I support FLOSS... But pretending that anything else does enough for many orgs is delusional. There is work and pain to get through to even have a workable solution... And it won't be as good for a long while.

Massive cost savings are one of the bigger motivators... But that will be offset by the need for more internal staff.