You are ignoring historical large oil spills that did not produce the effect you claim.
Look up the PEMEX Ixtoc 1 for a Gulf of Mexico example.
Good point. The PEMEX Ixtoc spill in 1978 was larger than the BP spill, and lasted for nine months(!) before Red Adair stopped it.
PEMEX oil washed up all over the Gulf coast - but PEMEX claimed sovereign immunity and didn’t pay a dime of compensation.