many comments have pointed out that miners can choose to not include particular transactions. Miners can also attempt to re-org blocks that contain particular transactions. If you had enough hashrate, you could keep transactions out of the blockchain by excluding them and refusing to build on blocks that contain them.

That would take more than half the hashrate (I haven't dont the math on what number would be needed, would be a nice simulation to run). So it's not likely under the current incentive structures