Much to unpack there. OP_RETURN is deliberately the most stupid of all op-codes. It does nothing but with lots of data. Nodes do not enforce whatever you want to do on top of OP_RETURN, so no, it doesn't turn Bitcoin into Ethereum. $50+ transaction fees will be required for Bitcoin's success at some point but the monkey picture spammers moved on. They don't have that deep pockets to sustain this attack. They started with pictures on Bitcoin but quickly realized that it has to be some launch date events to actually drive fees in a disruptive way. That made nobody rich and the few stories where it did - are probably just money laundering, so the attackers can't bet on gullible people falling for this indefinitely. They would need other deep pockets for a sustained attack. Increasing the blocksize is not a fix ever. We need to improve layers on top of the base chain if we want more people to have actual self-custody. With covenants enforced by miners we could scale Bitcoin by x100 without needing 100MB blocks and therefore with improved privacy.