I agree except the following:Synthetic oil advantages: longer drain intervals, better flow - gets to critical components faster, can promote longer engine life due to using smaller molecular particles vs conventional oil, best cost per mile depending on drain interval, lowers component friction over conventional oil.
Using full synthetic oil at its maximum drain interval offers the same protection as conventional oil does at its maximum drain interval. Using synthetic oil and draining it early is still more beneficial for the engine over conventional oil, although you lose some of the cost savings.
Based on oil analysis results, it is debatable whether using synthetic oil can extend your oil change interval. Conventional oil when changed at recommended OCI meet all oil criteria for engine protection. While synthetic oil if changed at extended OCI meet only most oil criteria. The conclusion is that although synthetic oil is far superior than conventional oil, it is only by following the recommended OCI that will give you the guaranteed results.
In terms of lubricating properties, synthetic oil only offers around 1% better lubrication than conventional oil at normal operating temperatures.
Again, under normal driving conditions of the general public, synthetic motor oil is a total waste of money. However, if you drive aggressively or in extreme weather, then you will need the extra protection offered by synthetics. But you still have to stick with the recommended OCI unless the oil is specifically formulated for extended use.