I actually have a proposal for my own language (spanish). It's written in a jokingly manner, but here it is: https://github.com/Calcoph/espa-ol-dos

The good thing about Spanish is that if you know the rules, you know how to pronounce a word when you see it written. However, if you hear it, it is ambiguous as to how it is written. So my proposal for spanish makes each letter have 1 sound and 1 sound only. And each sound is represented by a single letter.

A similar thing to that would already massively improve English. And that's just changing how the words are written, without changing the grammar at all.

Notice how that changes the easiest part of the language to change. You don't need to change grammar, or words used, or pronunciation.

Just having the sounds and the text be consistent with each other makes the language massively easier to learn. In addition, you wouldn't have one different way to pronounce each word per town in England. So even if you learned English from a texan, you would still be able to communicate perfectly with a Liverpool Englishman.

Even if local accents form, everyone would know how to fall back to the "correct" pronunciation if they see they're talking to a foreigner and are having trouble communicating.

Of course, all other aspects of English are a clusterfuck too, but you gotta start somewhere. And I think it's best to start with the high impact low hanging fruit.

EDIT: I just noticed I didn't completely read your comment. My proposal is basically the same.

Doesn't make it an excuse.

If you want a language to be used universally, it must not be a clusterfuck.

If it is a clusterfuck, it's easier to make excuses to not adopt the language. So it will fail in becoming a universal language.

"Why would I learn English to communicate with you? You should learn Spanish to communicate with me! Since English has X and Y issues that Spanish doesn't have".