Hi Ryota
Hope you are doing well and thank you for reaching out.
Your tenant users do not need an Adobe Acrobat subscription, or an Adobe ID to view the PDFs, view bookmarks, search a PDF, or comment and annotate PDFs. Once you have installed Adobe Acrobat for SharePoint and OneDrive across the tenant, all the tenant users automatically have access to these application features and can use it.
However, To Create, Organize, Combine, or Export a PDF, the tenant users will need an Adobe Acrobat subscription, and an Adobe ID. Even though all users can see these options in their respective accounts, only the users with an active subscription will be able to use these functions.
For more information please check out the help page: https://helpx.adobe.com/document-cloud/help/office365-configuring-sharepoint-onedrive.html#faq
Regards
Amal