Oil air filters while good in their day are not as good at filtering the air as a modern paper element tests show. Turbos need clean air to last, even small particles building up on the vanes cause imbalance.
An oil bath filter in good order will remove 95% of particles while paper does 98.5% when new with the performance improving to 99% and over with some use. This info comes from the Tractor world where good filtering is needed for engine life and performance
Oil costs have gone up over time while the price of making quality paper elements has gone down.
Disadvantage of oil unit is you have to mount it vertical. Paper can be fitted at any angle.