I don't know about some others, I don't think there's a problem with centralisation as such, just when things are as centralised as they are currently XD A bunch of small centralised things still registers as distributed to me so a bunch of little kinda-decentralised dapps operating on a mostly distributed network is fine. If someone doesn't like something on a dapp they can decide if they dislike it enough to want to jump ship or if the other features make it worth putting up with the thing they don't like, or if they have the inclination to spin up their own thing without the things they didn't like. The only way we'd be able to completely avoid centralisation is to do something like what Akasha is doing where everyone is running their own nodes.

One of the decentralised/distributed socnet things (not on a blockchain) I was playing with some years ago had a solution to the anonymity/pseudonymity issue by utilising profiles. From memory you could have as many profiles as you wanted with a single account, and you could have different display names and avatars for each account, and add different people to each account. I can't remember if contact overlap was allowed, but basically anyone you added as friends on a profile would only see that profile. You of course had to take some care if you wanted your work profile to not find out about your bdsm profile but otherwise it seemed to nicely handle cases where you wanted to use your legal name for family and work contacts but were known by some psudonym to online friends.

I don't know how capable steem dapps would be of that though.