There was a theory in the XIX / early XX century that full literacy was impossible without the Latin script but such claims are ridiculous especially for Arabic which is an alphabetic script already. China has higher literacy rates than Vietnam, for example.
I don't think the many composition rules of Unicode are really necessary, though. Maybe as an extension for academic work or artistic compositions but not for computing.
If all we had were movable types, all of these language users would find a way to write their language that wouldn't require a Turing-complete computer on each glyph. Now the Unicode gods pander to some of these computer-hostile scripts making the users of different scripts feel slighted.
In both cases, the original plan was for Chinese characters to fall out of use entirely via gradual simplifications, but in both cases the simplifications stopped soon after the first planned stages and it seems very unlikely it would be a popular initiative at this stage. Basically what happened in both cases was the equivalent of a spelling reform, not the elimination of a writing system.
In the case of Japanese, it seems there is some regret around simplification because characters not in the 常用漢字表 do not have the component simplifications applied that the standardised characters do (for instance, 攪拌 is more commonly used than 撹拌 despite the 覚 component being the "modern" simplified form -- and there are characters with no simplified form like the first character in 艱難, first character in 辻褄, or 迄).