To be clear, I'm not particularly advocating for making english a phonetic language. I'm just saying it being non-phonetic does cause issues (and makes it frustrating, but also shows a very interesting history).
Assuming we wanted to make English a phonetic language, then your question is kind of moot: phonetic means we need to pick the pronunciation rules for phonemes, which would make other ways to pronounce these phonemes incorrect. Some of currently-correct english would become incorrect english.
> For example, I would guess that 50% of English speakers are non-rhotic
Note that accent isn't really what people talk about when they complain about pronunciation. The problem is that there's no mapping from letters to phoneme in any english accent: laughter/slaughter, draught/draught, G(a)vin/D(a)vid...
All those examples follow the linguistic patterns of the languages they come from. They aren't arbitrary, they just don't teach us the context when we're learning as children.
Of course there’s always reasons. Teaching it to children isn’t really a solution: you’d need to know where words come from before reading them correctly, and also many people don’t learn English as children.
Phonetic languages do borrow words from other languages too, they adapt them to their own language keeping the pronunciation (the only example coming to mind right now is the Czech for sandwich, sendvič). English could do that just fine being phonetic was a goal
You would know where words came from based on the way they're spelt. That would let you know how to pronounce them. It's the exact same thing people do now we just do it without thinking.
The systems at work in English are not nonsensical like people like to parrot. To say it's not phonetic is just wrong on every level as well.
Frankly I'm fine with the historical oddities that have led to modern English. If non native speakers have issues, that's tough luck for them!
Assuming we wanted to make English a phonetic language, then your question is kind of moot: phonetic means we need to pick the pronunciation rules for phonemes, which would make other ways to pronounce these phonemes incorrect. Some of currently-correct english would become incorrect english.
> For example, I would guess that 50% of English speakers are non-rhotic
Note that accent isn't really what people talk about when they complain about pronunciation. The problem is that there's no mapping from letters to phoneme in any english accent: laughter/slaughter, draught/draught, G(a)vin/D(a)vid...