If you run it with arg1, won’t it run them all?

Yes, that is the intention. When you’re following some guide online and it requires you use some “software”, you may not know how to install that software.

This install.sh script tries package managers, because one of them will probably work. Others will fail.

For example, installing numpy (python package): pip install succeeds and all the other ones (hopefully) fail.

Installing libcurl4-openssl-dev (curl with openssl library file): apt-get install works and all other ones (hopefully) fails.

Longer and more thorough explanation:

https://www.explainxkcd.com/wiki/index.php/1654:_Universal_Install_Script

https://github.com/Override92/AiSList/blob/main/AiSList/aislist_blocklist.txt

Looks like this is their source.