It's hard to see the value of Steem when there are zero dapps on the platform but every app falsely claims to be decentralized.
The one dapp on Steem (blogging) doesn't gain much value from being decentralized, especially when all the frontends currently allow censorship by downvote.
As you say, the distribution is currently unique, but nothing stops a clone from coming around. Such is open source development. The one thing you can't clone the community, which is the ultimate variable that gives these projects value.
You can't clone the community, but the community grows on top of the system rather than a necessary part of it. The smaller a community is, the easier it is to transplant.
Also, one would argue that censorship isn't happening by downvote, but rather access control.