Not to be flippant, but in what way is Excel not a no-code / self-service BI / Data Analytics tool? Or where Google Sheets is heading? Serious question. The average non-technical user goes first to Excel or Excel-like things.
I don't think Excel or Google Sheets are the right interface for diverse data sources that have different query styles and different connection types. Visually the space in each Cell is just pretty constrained.
I am building an open source tool [0] for these kinds of workflows where you need to combine queries, scripting in Python/JavaScript/etc, graphing, dashboards, email exports in one place. It's very similar to tablum.io (this post) but instead of doing any ETL it's just a smart client for joining data client-side.
Excel applications also tend to start rather innocently where something rather simple is programmed in the cellular structure. People quickly feel empowered and begin adding more and more dynamic aspects. At some point spreadsheet based applications turn more into some unmaintainble monstrosity that have all sorts of business and application logic embedded in them that need to get handed elsewhere and someone else familiar with "code" or software design has to translate everything to.
I've been involved in more of this than I care to admit for business applications and it's usually a nightmare because the applications become more critical to the business than anyone but the spreadsheet maintainer is aware of. Suddenly something new and time critical is needed or an error is discovered and the person who created it largely can't remember everything they created and why, so it turns into an software archeological endeavor.
I've seen notebooks with dozens of sheets containing all sorts of embedded data structures on different sheet with all sorts of relationships inside and outside of sheets and nightmare chains of conditionals added in that I've had to sift through.
Sometimes the user then discovers macros or VBA and it becomes a dice roll if things are better or worse (usually better because at least you can quickly follow all the embedded relationships even if they're not well structured unlike logic embedded in cells with all sorts of spatial references you need 10 copies open to trace and debug).
Excel is hardly "no code" it just has a nice beginner learning curve that gets people into dangerous situations before they know they are. I'm not entirely sure about the direction of Google Sheets as I haven't used it in years.