Hashtags are used by many people to curate good quality content. Many feed readers now rely on Hashtags. Hence if you want to increase reach of your content, you should choose hashtags quite thoughfully.
There are many tools like Hashtagify, which gives you score based on impact of hashtags and some relevant hashtags which goes with it. This is how you can select the relevant hashtags.
There are some other factors like Memorability, Ease of writing etc. So use of smaller hashtags is recommended.