High enagagment with zero hashtags - how?

I have noticed an account in a similar niche that is doing very well. They do not use any hash tags but seem to have legit likes and comments on all of their posts.

I want to know how is this method working?

My guess would be they bought an account or switched an existing one, deleted all their posts and started posting again with their new niche.

If you want to know which account I can pm you.

they probably deleted their old pics, that is what I do too.