Because when you buy it you immediately develop finer taste for scotch etc.
There are numerous topics (hundreds, literally) about that topic. European manufacturers have far more stringent standards for oils. They have approvals, basically telling customer you need for example MB229.5 in your MB, get oil that is approved for that specification.
Due to demands of European engines, usually with high power density, very high internal temperatures to lower consumption and extract more power, longer OCI etc. Also, oils that are recommended have higher HTHS, which is what actually matters. those approvals are very demanding.
Take into consideration that in Europe they rarely sell HM oils. I personally never seen it. And those taxi MB’s still rack up million miles.
In European section you have all you need to know and more.