yep, while mineral oil is above WD40 in terms of staying power, it does evaporate quicker than chain lube from name brands, so you do need to thicken it a bit.

generally if you ride in places with a lot of rain, or live in an area with plenty of humidity (and salt) you want a wet lube. the wetter it is, the thicker you want your lube to be, at the end of the spectrum you have white lithium grease right on the chain

for arid places, a dry lube like wax will suffice, but a light lube similar to triflo or goldlink pro are good too.

it's always an experiment, I find, since there doesn't seem to be a 100% guaranteed answer for this.