Thank you for your answer! 😊
It's probably a bit overkill for my use case as I just need to aggregate env variables into one file for localhost only.

I'm using dotenv-cli and adding it to every npm script but that's a bit redundant.

Okay, then just for inspiration 2 approaches I have taken in the past:

Shared Config Package with runtime loading

One shared package for configuration, that you import, which also takes care of loading the .env file. So when it is imported the first time (by checking wether the env vars are already set).

require('dotenv').config()

Prefixing scripts

You seem to be doing a version of this. But instead of doing it with every script, you can prefix the program / cli you are running instead of every script.
To prefix all commands that are run by yarn. I for example have used it in the past to execute nx with more memory.

    "scripts": {
        "nx": "NODE_OPTIONS='--max_old_space_size=8192' nx",
    }

So whenever I run yarn nx, it is run with that. You can do the same to prefix your command with dotenv-cli and then e.g. run turbo always with dotenv beforehand.