[noosphr]

One I can say for sure is Serbian. Italian looks like it does. Finnish, Hungarian, Georgian, Armenian, Albanian, Turkish and Korean are all ones I've heard are to a lesser or greater degree, but I don't know enough to say either way.

[kortex]

Standard Italian speakers in Rome struggle to understand Ciociaro dialect, which is from the region on the outskirts of Rome. Take "n'coppa" - spelled with a "c" but very much pronounced /ŋgopa/ with a voiced [g]. I dont even have a reference point for Sicilian but that really pushes the bounds of the dialect/language distinction.

That's one example, from a language with ~70M native speakers, in a geographically tight region.

Likewise, all your other languages (sans Turkiye) are very compact geographically with small speaker bases. And Turkish undoubtedly has large aspects of forced standardization and dialect extinction.

English is spoken by 1.5 billion, by ESL speakers from basically every language tree, across the world. Try to get folks from Boston, Brooklyn, Philly, and Albany in a room and get them to agree on a phonetic spelling.

[accidentallfact]

People always overestimate how 'phonetic' their language is, because nobody actually uses phonemes in regular speech. In Korean in particular, there doesn't even seem to be any obvious correspondence between what is written, and what is actually said.

Foreign accents don't come from any inherent inability to learn language after X years of age. They come from people pronouncing languages as they are written, and virtually no language is like that in reality.

[DiogenesKynikos]

Foreign accents come from both.

It's true that when studying a foreign language, learning to read too early can harm your pronunciation. However, it is very difficult to learn new sounds that have no equivalent in your native language, and some languages have very restrictive phonology (like Italian and Japanese requiring a vowel at the end of every word) that their native speakers struggle to break out of.