Eventually your catalytic converter will clog up and that won't suit well with your engine mgt. or the local smog tester if you live in an area where that's required.
If it's getting past your valves guides, you'll certainly have increased carbon build-up in the head. If the oil rings on the pistons are not holding up, I suppose this could cause gradual wear on the cyl. wall(s).
Where's the oil going? Its' either leaking out or being consumed by the engine. A combination of compression test and leak-down test can indicate why it's disappearing if it's being consumed.
A visual inspection will give indication of a leakage problem. It's likely you have a combination of the two - leaking and consumption.
I realize money doesn't grow on trees, but if your oil loss is indeed substantial, you'll pay a higher price to correct the problem if you allow it to go uncorrected indefinitely.
My 2 cents.
1991 300-SEL - Model 126
M103 - SOHC
James Madison - Oppressors can tyrannize only when they achieve a standing army, an enslaved press, and a disarmed populace.
Liberty Firearms Training - After years of trying to regulate California criminals with a never ending stream of gun control laws they have still not given up with the belief that if they make something a crime that criminals will miraculously start obeying the law.