Thanks, Олег Ляшук for reading the article, on your question, there are many benefits of adding unsubscribe.

1. If User leaves the page before the response comes in, there will be a memory leak if you have not added a unsubscribe manually.

2. if the response never comes before the user leaves the view, there will be a leak again.

finally, Unsubscribing is a MUST if you want a deterministic behavior on all network speeds