Do you lose your identity when you change your accent?

that's silly. accent is part of language. if you're going to commit to learning a new languge, you have to make an effort to pronounce words properly as much as grammar and vocab. otherwise, you might end up saying a completely different word (one that may even be offensive in that language). if an American speaks your language with an American accent, it would sound wrong too, wouldn't it?

I tried to reduce my upper Midwest accent (as a native English speaker in the US), and while I don’t think I lost my identity, I do regret it. I should not have been worried about sounding like I am from where I am from.

Stop worrying about what other people think about your achievements. If you want your accent keep it. If you don't don't and if anyone tells you that you are wrong to do so tell them they can respect your choice or leave your life.

I think it can be tricky, because the monolingualism and common informality of the predominant culture encourages concepts of speaking naturally. It is so much so that people are discouraged from deviating from what others perceive as their nature. However, learning a language is often aspirational! The acceptability of switching accents is also coded by the predominant media: it’s always been okay for a certain Southerner to speak like a certain Northerner but often not the other way around. Southerners Beyoncé and Britney Spears, for example, learnt over time to speak in ways that most resonated with Americans generally. I think the ultimate thought-experiment is how would one perceive a European with fairly adequate English switching between an American and British accent. It seems it would be perceived as something akin to a lie by some, despite making great sense. I could catch on to a few accents quickly or smoothly enough for others not to perceive me as deviant, but I was so blessed as to come up in places where accent-switching was normal. However, to perfect another accent is rather difficult after a certain age, and I often refuse to say certain things a certain way just because it discomfits me, despite being able. To be honest, I also live in a place with many immigrants and my ears are tuned enough to say I know no one personally who has absolutely perfected a foreign accent. I, however, know many people who sound somewhat like their parents.

It depends on what you mean by "change your pronunciation." Most languages have completely distinct pronunciation patterns that don't exist in other languages. If you can't produce these at least somewhat effectively, people will have a hard time understanding you. So of course you're changing your pronunciation, because you have to. Being understood is important, to the point of overriding all other considerations within reason. But if you're talking about wiping away all traces of a foreign accent, then I can kinda see the point. Maybe. The reality is that every individual person has an accent all their own. In a given region the individual variations are usually so minor that you just hear it as part of the person's voice, and you don't think of it as an "accent." But then you have people whose accent varies further. My accent sometimes confuses people because I lived in four different cities growing up and picked up characteristics of each. But it's part of who I am because it reflects the story of my life. "Identity" feels like an overstatement, yet there's something to that idea.

only if you base your identity on your accent and that’s stupid as hell

As long as you can be understood clearly, I don’t see any reason to alter your accent. Where people struggle to understand you or follow your speech patterns, though, it makes sense to adapt your accent so you converse freely. This isn’t unique to ESL. I’m a native speaker but will slow down and moderate my accent (lowland Scottish) when speaking to non native speakers, or even native speakers who’re not familiar with the accent (like southern English or Americans). It’s not losing your identity, it’s just being polite.

They don't lose their identity, but they shouldn't change their accent. They should concentrate on the quality of their English and general pronunciation.

One thing I noticed is that, for example, Germans might say something like "They had a bad german accent". I think with English we don't do that unless the person is trying to imitate a specific accent (like an actor). Otherwise we just say "[country/region] accent". Also accents change naturally over time, when you move and live surrounded by people talking a certain way you will pick some of that up without conscious effort. Likewise when you go back to where you were from you'll probably slip back into that accent.

No? Making a different sound doesnt erase who you are.

I consider personality, culture, actions, and personal choices to be far more identity-significant than accent. Many people who had some English immersion while still a kid speak native-sounding English; likewise, people whose English teachers focused hard on pronunciation, or who focused hard on it themselves, might have no discernible accent identifying their native language. Should that make them less a member of their native culture? I'm a native English speaker, but learned Spanish pronunciation in grade school from a friend's family who spoke Spanish at home, and when I started actually learning Spanish, I could speak it without a noticeable English accent. I have never felt that as any loss of identity. Accent can be fluid, too, even within the same language. A high-school friend raised in a different part of the US was embarrassed by her original accent and diligently eradicated it. Another friend grew up in the US South and has mostly left that accent behind, but it comes back full strength whenever she's talking to or about her relatives. A college roommate came back from a year in Australia with an Australian accent that lasted for months. My brother's currently working in the UK and making no effort to pick up the accent, but I've noticed he's using more and more British words and phrases.