I am not a power user of either, and I absolutely detest when someone insists on using Excel. Sharing and collaboration is such a giant pain, and it's like going backwards in time to the 90's with e-mailed versions of files back and forth. Our org does not have a MS 365 license, so I'm unsure of Microsoft's web versions of Excel or how good they happen to be these days. I know users of it who complain though, and end up using it locally on their workstation like the olden days.

Most of my use is incredibly simple and used for project planning, inventory counting, lists of things that are split up into status/to-dos among multiple people, etc.

I've also never had a use for "Advanced" powerpoint, so the simplicity of google slides is a breath of fresh are as I only ever use the 10% most common feature set.

I actually get a bit of anxiety when someone sends me an excel sheet these days. It's usually going to be overly complex using clever methods, and that person is going to be a real pain to work with on iterating anything most of the time.

I've noted some very rare and specific times Excel is warranted though - such as our CFO creating complex financial modeling. For those uses I totally get that Google Sheets would be like working with handcuffs on.