In my understanding, it is like this: The 2-stroke-mix enters the crankcase together with the air as a kind of mist or spray. During operation, the crankcase is getting warm, so the petrol evaporates leaving the oil behind. The oil is deposited on the surfaces. A few drips are enough for ball and roller bearings. They don’t need to be absolutely soaked Also enough for the piston. Remember, there are oil scraper rings in 4-stroke pistons to avoid that too much oil comes up at the side of the pistons.
Some bearings may have kind of oil catchers, using centrifugal forces.
Old 2-stroke engines with friction bearings or need more oil, so they need a mix of 1:25…1:33 instead of 1:50…1:100 (enough for modern engines with good oils).
Of course, a part of it is always carried away and combusted, but new oil is constantly coming in with the petrol.
I have an older motorcycle with a single cylinder 250ccm two stroke engine, which I overhauled. After running in with 1:50, I reduced the ratio to 1:75. When I opened the crankcase, there was enough oil everywhere. The piston an rings were oily, the crankshaft and rod and even a small lake of oil at the bottom.
Too much oil just causes an “octopus-effect” because of a smokey exhaust and unnecessary carbon deposits on piston, piston-rings and exhaust without any benefit for the bearing-life.