Sadly Excel for Mac is the main thing keeping me from switching to Linux. OpenOffice/LO are ok for very basic documents but I routinely deal with files that they can't handle.
Google Sheets straight up fails if you try to upload files in that format. No preview available and no option to work around. So I would have to open the file in Excel anyway.
Relatively new versions of LibreOffice are capable of opening simple files, but once you get into features like named ranges LO fails.
So even if the UI is acceptable, failures on data import force me to keep a copy of Excel around. Keep a VM with Excel for Windows around just in case files don't work in Excel for Mac, but I've used it maybe once in the last 6 months.
For example, if you have an index then a tiny kerning shift can bump an item to a new page and screw up your numbering.
It really depends on the types of documents you're dealing with. Some are hell, others are a no-brainer.
It's good to search for duplicates first or see this filterable list of the most popular dupes: https://bugs.documentfoundation.org/duplicates.cgi
You could try office's web app thing if you are mostly a read only excel user.
You could try SoftMaker Office.
Quote: "No other spreadsheet is as compatible with Microsoft Excel as PlanMaker 2016. Both the old .xls files (Microsoft Excel 5.0 and higher) and the modern .xlsx files from Excel 2007 to 2016 are displayed true to the original and saved reliably. This guarantees trouble-free data exchange with Excel users."
But I will say that linux has come miles and miles. My transition from Windows to full time linux by way of Ubuntu was incredibly seamless. The only thing I really miss is Excel.