The government is allowed to suppress your constitutional rights in cases where it’s narrowly tailored to a legitimate government interest (the strict scrutiny standard). This may seem suspect, but it allows the government to do things like prevent people from bringing guns into schools or planes, or spreading private information or harmful lies about others, or being overtly loud when their neighbors are trying to sleep. It does require a high burden of proof from the potential violating body, so it’s not done casually.

For red flag laws, I imagine temporarily seizing the guns of someone who a judge is convinced is a significant danger to themselves or others would meet this standard. From what the other commenter said, it sounds like it isn’t done casually in practice. We are missing parts of the story that may make it seem prudent.