Op want to upload a file to a web GUI and print it from there, not share printers with other computer/ devices.

Also, scanservejs is the the sane web GUI to actually do the same with scanner.

For scanning it make sense as there are no shared scanning solutions across platforms. For printing, it’s of little use as other pointed out you can print to cups from anything basically.

But o get the need for a web printing page, as uploading a file and hit print button is a zero setup, and while simple even remote cups printing is not 0% extra setup, you have at the very least to select a printer or hit “share as” and select a print service (android). YMMV