That’s a very good idea.
Beside the number of permutations it gives, another benefit of using three words is they could form the border of the QR code, with the fourth side being the domain name

Paper may be old-fashioned but I need something light for the carrier pigeon

My biggest bugbear relating to this is the lack of a short text alternative for QR codes, especially with long URLs.
If the URL is too long to fit into a QR code, then it’s also too long for me to type in manually!

I find it handy for writing down a URL on paper