All else being equal, potentially - although as I mentioned there have been cases where one engine falling off a 4 engine aircraft hit another in the process. But ETOPS certification is based on it being demonstrated that engines are sufficiently reliable that the probability of an independent failure is incredibly unlikely, and also requires that operators have a stricter maintenance process. The only dual engine failures on modern two-engine aircraft I can think of off-hand have been fuel exhaustion (either actually being out of fuel, or ice blocking fuel filters in the case of BA38), and would have affected 4-engine aircraft just as badly.

> Wouldn't one expect more engines to be safer?

Right, the more engines the better…

Engine failure is very dangerous. 4 engines are twice as likely to have a major failure than 2.

(despite having "fuses" so an engine can depart without taking much of the wing with it, there are many cases of single engine failure bringing down the airplane)

There have been zero lives and airframes lost due to independent double engine failure during trans-oceanic ETOPS.