As a young engineering student, I picked up the extremely strong impression that linkedin was for MBA students, not me, so I enthusiastically never joined yet another obviously suit-centered social network thingie.
I have yet to be convinced that this impression was wrong.
LinkedIn as a host of your CV with potential recruiters finding you is pretty ok to be honest, there's nothing else there to experience though, I don't ever want to look at my feed, I ignore 90% of the recruiter spam. Still, I got my current job from a recruiter contacting me, at a major tech company you are probably aware of.
You don't need it to be a social network thingie, it can just be a showcase of your CV that you can check messages from recruiters/other people hiring when you feel like it, ignoring them is also quite expected so you don't lose anything in the end.
As someone in this industry for 20+ years, you are not gaining anything by enthusiastically ignoring it, it doesn't take my attention or care and it can give you pretty good opportunities sometimes.
In summary: in my opinion your impression is wrong, LinkedIn is definitely not a necessity but just by sheer volume you'll find many great opportunities there, at least in the tech/tech-adjacent industry.
Maybe the social aspect is, but it's just another place to have your resume listed for recruiters to search and look for jobs on.
Readers, Spare me the stories of how you just phone your friends for nearly 7figure jobs please and how job searches imply your not worth hiring please...
I mean sure, you can take the “high road” and belittle its users and how they have a different area of focus than yours, but the reality is that skipping linkedin will 100% make you miss engineering opportunities.
I have yet to be convinced that this impression was wrong.