What advantages are there to painting the inside of the block?

Soo... doing my current motor, i actually have a 40+ year old can of glyptal and was going to do it.. torched the block like 3 times to make sure it was clean, then didn't do it. The thing about sliding easier on the paint is obviously true, but after there is a wet coat of oil on the valley walls wouldn't it basically make anymore more oil slide just as easy? You are giving up a tiny bit to coat the surface at the start.. but if that much is going to be an issue.. you need more oil anyway :)

P.S. the main reason i decided not to do mine is, just a street beater motor... so not really needed