How important is journal prestige when researchers publish a paper?
In principle, publishing in a prestigious journal may help reach many readers and/or boost your career. The practice of judging articles by the journals they appear in is widespread although also widely denounced (cf the San Francisco Declaration on Research Assessment).
In practice, a lot depends on your field of research, your career stage, and the organizations that pay your salary and/or grants. At one extreme, some people would boycott &quot;luxury journals&quot; as a matter of principle (Randy Schekman) or ignore journals altogether and just post their results on arXiv (Grigori Perelman). At the other extreme, some will tell you that their careers entirely depend on how many articles they publish in their discipline's elite journals.