It is. They know everything about you. Even every store you have shopped at knows a lot about you. It really doesn’t take much interaction for a company to get a lot of info. It’s relatively easy to get an email and from there, if they wanted, they can get the rest of your profile from a 3rd party who has your data all matched up already. They can also build your profile pretty easily themselves as well.
Product development. Anything associated with building software products get a lot of traction on LinkedIn