If a filter is able to do a really effective job of straining debris out of the oil, it needs to have media with small enough pores that a tiny volume of oil trickles through it.
Either that or it needs to be REALLY big if a full flow filter, so that more oil can get thru a multitude of those small pores.
What you said is true. A full flow "big chunk" filter AND a small pore bypass filter would be a good solution.
Getting the dirt out of the oil makes engines last longer. Filtration is one way. The other way is to change the oil at ridiculously short intervals.
