I must say I'm not surprised. Those are very active, advertise themselves outside there own platform, and an have an easy and friendly onboarding process. However they are not fully decentralised like Hive.
Which is unjustified considering that Hive if far more decentralized then the top three and far more active then Steem and Blurt. If you have a Sourceforge account you might want to consider writing a review:
I will do so later — but it won't be a ⭐️⭐️⭐️⭐️⭐️ — there is room for improvement.