I think the answer is no. It is mentioned in the same way in Pubmed for the same journal so my letters count the same and they can also generate another research item in RG. They are, after all, often reviewed in the same way. Nevertheless, I would not include it in my CV in the same way.
I think letters to the editor still serve a very important function. It makes people who write articles more accountable and they can be held responsible for what they say. Accountability is an assurance that an individual or organization is evaluated on its performance or behavior related to something for which it is responsible.
It is, to me, very important in science and lots of other areas.