even if; no matter (who, what, when...)
Expresses that even if a certain action or state is achieved, the expected result will not follow; it's useless or futile.
This pattern is used to say that even if you do something, it won't lead to the desired outcome. It often carries a tone of resignation or criticism, implying the effort is wasted. It's similar to saying 'even if' but with a stronger sense of futility. The result that follows is usually negative or expresses that nothing changes. For example, you might say this to someone who thinks working harder will solve a problem, but you believe it won't.
It is often paired with expressions like 無駄だ (useless) or 同じだ (the same), or with phrases like 〜ない (negative) to emphasize that the outcome won't change. Note that it is not used for hypotheticals that could be positive; it's exclusively for negative, disappointing results. In conversation, you might hear it in arguments or when giving a reality check.
This pattern is fairly formal and more common in written Japanese or in speeches. In casual speech, people might use 〜たって or 〜ても instead, which are less formal and more direct.