You are a native speaker, so please don't presume to know what is or isn't an issue for someone who speaks English as a second or third language.
I'm a native speaker, and I've taught English in Japan, Germany, England and the US. I'm discussing this from the experience of teaching thousands of students, of multiple nationalities, in private tuition and commercial language schools.
I've had hundreds of conversations with students who want to tell/ask me which kind of English accent is 'best' or 'correct' which is actually a fair enough question, if you're investing time and money in learning a language, but it leads nowhere with English. Ideas about the 'best' accent range from archaic RP British English ('the Queen's English is best, because England is the home of English and the Queen is the highest rank of English person') to strange, everywhere-and-nowhere blends of American accent (a Texan drawl with Boston Rs and Californian vowels best because America is the 'business and media centre of the modern world').
If English was spoken in just one country, you could identify the accent of the richest/highest in social status/most educated and make a case for that being the 'best'. (You'd have to be a raging snob, but you're paying for the English lessons, so that's your prerogative.)
But with such a widely-spoken language, which has entirely legitimate dialects in multiple nations, plus infinite regional accents within those -- any conversation about the 'best' English is meaningless, and usually descends into unpleasant, silly claims about the importance of good breeding, economic clout and 'I'll see you the American film industry and raise you SHAKESPEARE' and other finer points of cultural prestige. I've had this conversation a lot, and it gets both ludicrous and offensive, especially if students think that, because I'm English, I'll agree when they say that they would hate to have an Australian or Irish teacher, because that's a lazy/incorrect/inferior brand of English.
And I'm not saying all this to make some right-on point about equality, either, at the expense of my students' outcomes. IME, the students who continue insisting that regional accents or particular dialects of English are of lower rank than others, and want to sequester their own learning from its pollutions, are also a) most likely to be frustrated by spontaneous interactions with native speakers of any nation ('he was not speaking proper English!'), b) slowest to progress with speaking and comprehension in a group setting (no point talking to other students: their English is poor), c) able to comprehend a carefully enunciated, formalised language track, but completely at sea when trying to enjoy English language movies or TV shows, and d) overall less effective communicators, whatever their official level, even if they are confident at reading aloud and have excellent written English. It's just not a helpful mindset.
You won't understand until you are go to a language school and see for yourself how you learn through imitating your teacher.
This is not how anyone learns to speak a language. Your teacher isn't programming words and pronunciations into your brain. It's an interaction, and you are influenced from multiple sources. (Unless, as before: North Korea.)