Interesting. Probably, 500px is great for connecting like-minded photographers.
Threads
Great you decided to give Threads a try! Threads needs some time to learn what you offer to guess whom to show your posts. Happily, there is no "recycling" restriction on Threads like on Hive, so you can post your unnoticed images again later when your account is more visible.
@davideownzall assumes Threads prefer people to blog in their local languages - I also have this suspicion based on observations... It might be you need a bit more time to warm up your account if you blog in English. (These are only assumptions).
The toughest thing is to convert likes into subscribers but the fact that newbies can get such visibility makes me feel optimistic. I also hope Threads is even more generous as soon as it sees that a blogger posts consistently for a month or so.