I'd like you to go look at PRINCE2 and SSADM. Or read the original Royce paper - https://www.praxisframework.org/files/royce1970.pdf was written explicitly to term this Antipattern "Waterfall." (Note that Royce marks it as an antipattern.)

I discussed some of this in https://www.ebiester.com/agile/2023/04/22/what-agile-alterna... and it gives a little bit of history of the methods.

We are nearly 70 years into this discussion at this point. I'm sure Grace Hopper and John Mauchly were having discussions about this around UNIVAC programs.