PieFed Meta

But if one uses search to fetch my article from their instance and comment on it, shouldn’t my instance still receive the comment ?

Yes, but if you don't pass it on to subscribers then other users can't see each other's comments on their instance (unless they are on the same instance as each other).

Because I don’t really want to send content to instances, I just want the abovementioned scenario to work, basically the purpose I see in Lemmy as a blog is to enable readers to interact with me from their own instance, which solves the issue with CMS-powered blogs which whom people never interact with because of not wanting to create an account there.

With ActivityPub, people need to interact from their own instance, which means the content needs to be sent there.

A related concept is being able to use your account in one instance to be able to log in to a different site - effectively some sort of OAuth implementation (similar to "Log in with Google", "Log in with facebook").

The Canvas event set something up for this, where you could log in to their site by using a fediverse account from another instance. You entered your user, it then messaged you a code, and you would enter it in order to log in. Then you could participate. Their code is here: https://sc07.dev/sc07/fediverse-auth

However, this relies on the backend site implementing this custom setup.

Long story short, I don't think what you want actually exists (people come to your Lemmy instance, log in with their existing lemmy account, and comment directly on your site).

To use Lemmy as a blog, you'd have to fit into the existing structure (create posts to your blog community, people would subscribe from their own instance, view comments and add their own from their own instance). This would be like any other Lemmy post. Here is an example: https://no.lastname.nz/c/OurCamper (though this one isn't marked as moderator posts only, which it probably should be)

Interestingly, if I try to comment on a post my instance reports the federated activity was accepted by your instance, but it doesn't show if I look at your instance. It seems to be getting silently dropped (or some error is happening). Have you done anything special or is this the federation issue you see? If you want to push forward with using Lemmy I can try to help you troubleshoot.