I want to mention teapot. First an apology, it's not actually a good match for for question, sure, it's a curses spreadsheet, but it was made by someone who thought about the fundamentals of the problem a little too much. So it is probably a little too weird for someone who just wants to spreadsheet as Dan Bricklin intended.
https://www.syntax-k.de/projekte/teapot/
In short cell address are normalized @(1,2,3) instead of A1 or r1c1. real references so address rewriting hacks($A$1) are not needed. formula references so you can use a single master formula, and clocked expressions which allow circular dependencies/simulation.
Probably a little too different for casual use but worth taking a look at, if nothing else to challenge your ideas of what a spreadsheet has to be.
While looking up the website I found a rewrite in rust, which is cool I guess, someone is keeping the dream alive, I will leave a link to that as well.