mayo is meant to be used sparingly, not smothered all over everything. it's literally sulfur, rotting wine and butterfat, there's no nutritional value that comes out of mayonaisse
mixing into ingredients in small amounts adds creaminess and a little bit of savory salty flavor, and it actually tastes good that way. but like, if you're going to make your food 99% mayo, just take the healthy route and dump a pile of salt and egg protein on it instead