I've transcended the vanilla/framework arguments in favor of "do we even need a website for this?". I've discovered that when you start getting really cynical about the actual need for a web application - especially in B2B SaaS - you may become surprised at how far you can take the business without touching a browser. A vast majority of the hours I've spent building web sites & applications has been devoted to admini…
I've found that "send me a spreadsheet and I'll upload it" isn't a great user experience. It's just a big pile of cells, with no documentation (which they wouldn't read anyway).There are a billion things they can do wrong, and they get no feedback on it until I email it to them. They don't know what the options are for any field, and it's easy to enter a nonstandard value. A typo in a header row can lead to data loss…
The benefit would be that you have a fixed set of UI components available in Excel and don’t need to worry about styling and whatnot.