Hello ,
Excel is not a CRM. WhatsApp isn't one either.
Yet plenty of businesses run their sales process through spreadsheets, inboxes, WhatsApp chats, notebooks and memory.
Some have a CRM too. They've ended up with a sales Frankenstein stitched together from five different systems.
Others tried CRM, hated the admin, couldn't get the sales team to use it, and went back to Excel.