EFI don't dump as much raw fuel on the cylinder walls because it atomizes better and is more precise. Fuel is a bad lubricant. The EFI on modern engines also has the ability to turn on a CEL and let average people know when there is an issue, with a carb the vast majority of people will never know when it gets a little out of whack.

Better oil control means they can run lower tension and thickness rings and that means less friction.

OD trannys keeping RPM down when not needed to be high.

Hypereutechtic pistons are used in most engines now and the alloy is more slippery as well as tighter fittin in the bore at cold starts thereby reducing blowby of carbon and other harmfull substances. It expands less than forged or even old school cast.

Machining precision, the machine tollerances are held to a lot tighter standard again reducing friction.

Oil is much better now than 50 years ago, there was such wide variations in oil back then that you could not mix different brands a lot of times.

Better ignition systems like coil on plug ensure more complete combustion.

Better material in the bearings block and rings and cranks...

More thought is put into getting the engine to warm up faster thereby lowering emmisions caused on cold starts, also the cars are heavy forcing the engine to warm up faster to a more efficent temp. Higher temp thermostats also make the fuel evaportate faster keeping it out of the oil. Hot parts also generate less friction.

There is more also and some of these things are easily added to old engines and some are not.