We have items that become obsolete. We would like to keep the pages up because a lot of people don't know that when they try to replace an item. We would add language on that page telling them it has been replaced and what it has been replaced with.
Because these items no longer exist we do not want people to add them to the cart. I have found tutorials on how to remove the button from the item page by setting it as an attribute but that still leaves the button on both search results and category pages. I have tried the Amasty extension but that only removes it from the item page no the search results or category page and I don't think it will.
How about enabling out of stock products? Once you do that Mageno will displays out of stock items, but doesn't allow to put them to the cart, because ... well ... they're out of stock. Just make sure that the item is not backorderable.
Normally that would work but we use a strange stock system that this would throw off. I ended up using an Amasty extension that seems to have solved the problem.
You are concern how to remove the Add to Cart button for the specific item. This question may be helpful to other people who are in the same trouble because this is a popular problem in magento 2.
To me, I would try MAGENTO 2 HIDE PRICE because it offers me not only the best solution to remove the Add to Cart button for the specific item but also many other benefits:
Why don't you try MAGENTO 2 HIDE PRICE?