Well even though WD40 can be used as a lubricant it isn\'t actually a dedicated lubricant, it\'s water displacing and as such doesn\'t last as long as crc when used to lubricate. After a month or two if used on weather exposed things you\'ll get erosion eventually too.
I\'ve always found it quite good to use wd40 first on rusty bits and then follow up with crc.
Although if you\'re happy with its performance in the situations you\'re using it then i\'m not questioning that, go for gold.
The one I used it on rusted again after a month or so, but after using wd40 again to clean it up then using crc it was fine ever since. Although I haven\'t actually had a bike for years now o-o
The main use I had for it was if I had something anodized that got scratched you use wd40 and a scotch pad and it buffs it out