correct

if you have the correct chip, there are many advantages. the main point of the lambda sensor is to control the air/fuel mixture to a point that is where all the fuel that is injected has been burnt, rather than injecting too much and wasting it.

too much fuel also leaves deposits on the spark plugs, combustion chamber, pistons etc (used to be called coking up), and contaminates the oil meaning more frequent changes are needed.

so the main benefits are improved fuel economy (and fuel is not getting cheaper, so closed loop lambda control can pay for itself quite quickly) and a cleaner running engine.

there are probably better explanations than that on the 'net if you do a search