Why "make public" option on object is now removed?

There is a good post here https://aws.amazon.com/premiumsupport/knowledge-center/read-access-objects-s3-bucket/ on how to make a bucket public.

The procedure has changed. Currently, ACLs have been disabled by default for objects. A majority of modern use cases in Amazon S3 no longer require the use of ACLs, and AWS recommends that we disable ACLs except in unusual circumstances where you need to control access for each object individually.

For a situation where you want to enable public access to each object, you have to follow the below-given steps.

• Go to the bucket
• Go to Permissions
• Go to Object Ownership section
• Click Edit
• Select ACL enabled
• Change object ownership to Object writer.
• Save changes

Now you can go to the bucket again and select the relevant object which will have the enable public access option available to make the object public.