used Windows at work, but always used OpenSource at home, find it way more user friendly and certainly no wasted time booting.
Discussion
I do think Excel is the only Windows tool I couldn't replace (currently) with open source--the advanced tools (e.g. Power Query) really are a game-changer for analytics...will probably soon have some equivalents in Libre or Open Office, but still...
you could try gnucash for accounting?
No--it's really Power Query that I've used so much I'm now dependent...really opens so many doors for analytics...
But (really) as I think about it, it's Power Query I can't live without (and it's integration with Excel).
As a spreadsheet, Libre Office is perfectly adequate.