While I understand your desire for uncensored multimedia, there are some technical difficulties doing so. Let's assume that the witnesses increased the block size so that an image or even a video could be embedded in the blockchain. The servers that back youtube are many many terabytes of data. Orders of magnitude more storage than exist in a typical laptop or desktop. This is all contained and secured by hash in the blockchain. The blockchain would quickly grow to terabytes in size. In order to access this information would require a commercial server.
You would likely have to rely on a few services to host the data. The centralization of services is prone to censorship. What makes Steem censorship resistant is that it can be run by anyone on average hardware (<32 GB disk space, a decent single core processor, and 4-8 GB of RAM).
Until quantum computing and quantum storage is refined and affordable enough to be in our homes, storing that much data in a decentralized manner will be out of reach. The best solution is likely to have a centralized repository for multimedia and reference the media by hash. Using this technique it would be easy to determine if content is being censored. Worse than censorship is being lied to while being told a platform is open.
RE: We need to extend the censorship free aspect of the blockchain...