I'm aware of quite a few questions asking about the best way to handle messages on LinkedIn from recruiters, but I think this is different enough to warrant a question of its own.
There are quite a few recruiters who send me messages about vacancies, or telling me how they are interested in my CV, or asking me how I'm feeling at my current job very often. Some of them send me messages every two weeks, every month, some more often.
Due to me being quite happy in my current job, I'm not interested in pursuing new opportunities, thus my current response is something along the lines of:
Thanks for contacting me. Currently I'm not interested in new job opportunities but I'll let you know when the situation changes.
Taking into account that (1) I don't plan on changing jobs in the next few months, maybe years, and (2) I don't want to burn bridges with recruiters in my area, should I even bother replying? Or are these automated messages sent to the recruiter's network or potential candidates in the area and the recruiters don't care about negative answers? If I do need to respond, I send always the same message.
Update: most the messages are about vacancies that are a good fit for my tech stack. If I weren't happy with my job I would most likely be interested in most of these messages. Moreover, most of them don't seem to be some spam sent to dozens of random developers in the area. The problem isn't that the jobs aren't a good for me. The issue is that the messages are too frequent.