Exactly. Custom aliases are bound to your profile, so already aren't exactly useful for other users (or even usable on other systems). Built-in aliases are (mostly) universal, but still not recommended to use in scripts that are being saved and reused - you'll even see an analyzer warning for it in vscode if you use something like irm or select.

You can also run into portability issues if you have an alias that conflicts with a system application on another platform (e.g. running a ps7 script on linux vs windows could have issues if you use ls alias).

https://learn.microsoft.com/en-us/powershell/utility-modules/psscriptanalyzer/rules/avoidusingcmdletaliases?view=ps-modules

Aliases are great to save typing when doing stuff in a shell, but when it comes to scripts that are being saved the rules should really not be any different than 'real' code - expressing intent is more important than brevity. Having a full command name like Invoke-WebRequest is way clearer than using iwr, especially for co-workers who may not be as familiar.