Unicode is a vast standard and have many separate parts. Unicode the character set is a significant but miniscule part of it. You don't need much to support Unicode if you don't do display (or delegate the display to someone else, like web browsers). The conformance requirements are also loosely worded that you can declare many parts of them as unsupported and move on [1].

Unicode also packages an essential but (in hindsight) complex concept and process like "what is the word boundary" or "what are characters usable as a part of identifiers" into a neat algorithm and data table. The algorithm is more complex than the data, which is readily available for you. Assigning a new character to Unicode mostly means a change to that data, not to the algorithm. If you consider one should be able to display every assigned character as expected to be fully conforming to Unicode---I stress it's not true, but if we assume so---then there would be no conforming implementation of Unicode at all. All Unicode implementations just implement what they need to support.

[1] For example, the requirement C12 (https://www.unicode.org/versions/Unicode13.0.0/ch03.pdf#page...) specifies that you need to implement the Unicode Bidirectional algorithm only if you support right-to-left characters. In the other words you don't have to implement the Bidi algorithm for conformance.