2 years ago note composer was introduced in Obsidian after this thread (Merge notes and update backlinks) from the forum.
However, it still lacks one feature suggested in the thread - to leave the original name of the merged note as an alias whenever it is refereced.
Imagine merging [[machine intelligence]] into [[AI]]. Now all references are just [[AI]], [[AI]] and [[AI]]. But I’d rather have [[AI|Machine intelligence]] whenever the old file was mentioned.
I’d prefer to have this as an option when merging — I can imagine choosing differently depending on the note.
Have you checked the Obsidian42 Text Transporter plugin? It brings you closer to what you want sending block embeds to other files or copying blocks as aliases to be pasted into target files. Check it out, it might be just what you need 
Yes, this is simple and basic option that ought to be there when merging notes … can’t believe that they left this out.
And even weirder is that this request has so few likes…