When we say no cabal-install as a downside of stack, what exactly is meant by that? It’s relatively straightforward to write stack install cabal-install, and given stack exec --no-ghc-package-path zsh, you can use the stack provided ghc and the stack installed cabal-install binary pretty easily.
I currently use ghcup lately to manage cabal and ghc versions outside of stack, but for a long time, the stack based workflow for getting cabal-install and ghc was the only way I used either tool.