I kind of like some of the Brutalism takes on web design. Just throw away all decoration and live with the ugly world, “ugly” being subjective. I think excel sheets are actually quite beautiful.
Challenge the status quo :-) at the expense of coolness, dignity and comfort.
Part of conveying information should be about making the information easy to digest. Sometimes a spreadsheet fits that bill. Other times a crafted UI works better.
Excel sheets are essentially rectangular grid with borders. Grids have been used since the 60's in graphic design, primarily championed by the Swiss Grid System (Josef-muller brockmann, et. al).
So if you say that excel sheets are not a good instrument to convey information, you're saying that a grid like structure is not good at laying out information in a logical, understandable fashion. Which is provably false - everything from Tax forms to road signs, every bit of graphic design professionally conducted uses the grid system.
Think a bit deeper than just aesthetics and ask yourself, what exactly is an excel sheet? It is a bunch of boxes. Whether those are div elements or excel cells, what's the difference? Padding and margins?
One idea I have is to go back to the simpler days of MSDOS GUI. We can generate such a UI using some custom markdown, and for the most part it does simple CRUD, with plugin support for complicated stuff. The focus will be on speed (keyboard navigable with Windows alt+<letter> shortcuts), and brutalist UI in the form of MSDOS GUI.