Interesting.

I wouldn't consider myself a "pro" Excel user. I think my comprehension would be on the higher end of "basic", or maybe the lowest end of "intermediate".

That said, in all the years I've used spreadsheets, I guess I've never really thought I needed more than one value in a cell. I never really seriously considered putting JSON or something in there, and have been ok with just using more cells instead (especially since Office 2019 when they added dynamic arrays that allowed spillover).