The problem with that argument is that not everyone is OK with living a bare minimum cost of living life style. Also rewarding yourself for earning more can give you motivation to progress further.

I recommend fixing your spending at a %-age of your post tax income at a maximum. For me it is 50%, but that is on the conservative side for most people. I don't always spend 50%, but that is the max. I feel it is a good compromise between preparing for the future and rewarding yourself in the present