Looks really cool! I tried the install script and it asked me for my computer password. It feels really dangerous to give a random script from the internet my password. Could you maybe change this, so this is not necessary?
So elevated privileges are needed because we're installing using Docker Compose and you can't use Docker without some form of elevated privileges (most people always run it with sudo). MacOS is a slightly different story, but anyway.
The reason we use Docker Compose is because we need to not only deploy Mathesar, but also a Postgres database (if you're not using your own), and we want maximally simple installs and in-app upgrading (upgrading is implemented via Watchtower, which is basically fancy docker pulls with automatic container restarts).