Looking for a job in civil engineering. Why do people send invitations instead of calling? Is it reliable?

Most of them are unreliable, especially the one that tells you to go directly to other places, which is absolutely deceptive-MLM organization.

If it is around here, you can go and have a look.

I've been in this situation, too, and asked me to go directly, because my classmates and I voted for the same position at the same time and asked us to go directly.