No it can't. And counter to your point, more decentralized mining may make it even easier. Decentralization of mining has nothing to do with how full blocks are.
You're right, it's not coincidence. They're fleecing you. You've been convinced that mining on ocean and running knots is the morally superior stance.
I've been convinced that people can do harm, and harm tends to escalate. And forget Ocean - if you have a bitaxe in your closet, and think you're doing your part, then you should see that decentralization is the key. If someone comes to you with some money and a file and pays you to put it on bitcoin in the next block you hit, you will smile and take his money and that file is most likely going to die when your harddrive dies. That out of band transaction went nowhere. So we need to keep this trash out of band, and focus on mining. Lifting the filter is just the wrong strategy.
Mining is already sufficiently decentralized. Game theory dictate the structure will remain close to the current landscape. There will always be a few big miners. It's nice to have more little guys but it won't make Bitcoin any more secure to have more decentralization of miners. It will make it more secure just based on their being more hashrate. Mining decentralization matters most geographically, not so much separate actors.
Regardless, mining isn't an issue imo and I wrote an article recently if you're interested in reading it. Bitcoin is built to withstand any concern in this field. It's own immune system is the only thing that fixes it, and it does so every time. No single pool or actor is going to magically make anything better or more resilient. Bitcoin will do that on its own.
