Where do we begin? Google Sheets is one of the best spreadsheet tools, as an alternative to Excel, and for that, it works great! We've used it in our own business in-place of Excel, but for most things that you might think Google Sheets would be good for, you'd likely be better off using another tool like Airtable (but more on that later).
When talking to companies that are thinking of using it as their core CRM, we strongly advise against it. A spreadsheet should be left for exactly what it was built for, building complex financial reports, not sales outreach, or especially anything to do with relationships. Here's a candid answer to the FAQ, should I use Google Sheets as my CRM?