Hashtags were reintroduced by LinkedIn a little while ago; now it seems they are testing their value on the platform by 'forcing' some people to use them.
Hashtags can help people to find you when they are using the LinkedIn search tool, and it is usually a good idea to include a few relevant hashtags in your status updates – particularly if those hashtags are also amongst your top keywords.
You can also search for specific hashtags, which will bring up all content that includes that hashtag. So, for example, if I was interested in cycling, I could search for #cycling and then engage with all relevant content where I can add something of value/interest.
This again draws attention to yourself without selling and helps to send people to your profile page.
https://thenextweb.com/apps/2018/04/06/linkedin-hashtag-test/