So if you are using LinkedIn to find a job and open to new opportunities you are likely getting messages from lazy ass lying recruiters that are either not forthcoming on the position they are hiring for or just mass sending out copy pasta to anyone that will listen.
I remembered that there is an additional cost that these recruiters pay LinkedIn per InMail message to use their service and went looking thru the LinkedIn recruiter FAQ to see how the pricing works.
Apparently, the LinkedIn AI uses some pretty basic rules to charge the recruiter for sending these messages, normal prompt responses either using the generated quick responses or decline options enable the recruiter to reclaim their messages without cost, so they can try to scam someone else.
However, that AI function is only triggered if the InMail is accepted, declined, or responded to directly within 90 days of it being sent, only then is the head hunter credited back the cost of sending the InMail message.
So TLDR if you want a recruiter to pay for sending you shitty job offers or spam InMail messages leave the message pending response in your inbox for >90 days then decline. They will eat the cost of the original message and won't be able to contact you unless they send another InMail.
sauce: https://www.linkedin.com/help/recruiter/answer/a413322/inmail-message-responses-in-recruiter?lang=en