I think "for businesses" is probably the caveat here. It feels like a trope to mention it at this point, but I think the world would suffer greater consequences if, say, the Linux kernel broke.

I'd also argue that Excel isn't really the most "powerful" per se, but the most accessible and convenient for sure.

It is for sure the most widely utilized functional coding environment on the planet.

SAP or Salesforce is often the critical piece of software in many an organization. My current assignment (I don't work with SAP though, thankfully) is an energy company with ~3 million customers, each and everyone's data is managed in SAP along energy usage, billing/invoicing, the works. Small army of people managing and maintaining it, too.