Now days, Google has been introducing features for its user convenient, in such a way, Sharing features are more reliable for you.
Therefore, you can now publish a PDF file by just clicking on “Share” selecting “Get the link to share” and checking “Allow anyone with the link to view (no sign-in required)”. Although, your files can be publicly seen, yet you need to log in using your any Google Account.

Click to publish PDF Files automatically

As you know, spreadsheets hold a unique feature that lets you collaborate with anybody that received the link to the spreadsheet without any need of logging in.
Now this feature is available for Documents and Presentations too, therefore you can easily collaborate with more people.

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