Is UTF-8 the final character encoding for all future time?

It seems to me that Unicode is the “final” character encoding. I cannot imagine anything else replacing it at this point. I’m frankly confused about why UTF-16 and UTF-32 etc. exist at all, not to mention all the non-Unicode character encodings (unless for legacy purposes).

In my system, I’ve hardcoded UTF-8 as the one and only supported character encoding for my database, my source code files, and any data I create or import to my system. My system internally works solely in UTF-8. I cannot imagine ever needing to change this, for any reason.

Is there a reason I should expect this to change at some point? Will UTF-8 ever become “obsolete” and replaced by “UniversalCode-128” or something, which also includes the alphabets of later discovered nearby galaxies’ civilizations?