If there existed a single paper mill company that held 95% of the market, and they decided to refuse selling paper to a news paper, then I would consider that a

If there existed a single paper mill company that held 95% of the market, and they decided to refuse selling paper to a news paper, then I would consider that a problem. It might not look like censorship, but the practical effect is very much similar. In theory a news paper could go out and buy land, grow trees, cut them down, and mill them into sawdust, and chemically treat that sawdust in order to turn it into paper, and then finally press it and print it, but the likely outcome is almost deterministic. Thankfully we do not have that situation. Everything from forestry, wood cutters, sawmills, paper mills, printing presses and distribution is very much decentralized and have a healthy market with plenty of competition. It is so healthy that unless something is actually illegal, no one can stop someone from printing what they want. At most a company can do is create a small inconvenience. Server hosting is not that healthy but buying your own servers is much easier than producing paper, and the retail side of server hardware is healthy enough that preventing someone from buying servers would not be feasible. AWS does however have a demonstrated market power over companies that is very unhealthy so in my view they sit somewhere between a common carrier style regulated monopoly and a regular large company. If their decision to ban parler would have had minor effect on parler then we would not be having this conversation.