I bet a lot of people can’t figure out their gas mileage, how to get the correct ratio of gas/oil for a two stroke, build a deck, etc. because of the math. In my opinion more than 4th grade math is necessary for everyday life. And some basic geometry and algebra can be handy - not absolutely necessary, but handy.
And I see your points about the non-essential classes. I can understand colleges wanting to make students well rounded, but some of it does seem useless. Luckily I was able to avoid most of the humanities courses!
I bet you would use some geometry if you wanted to figure out the area under the curve on a dyno plot. You mean everyone doesn’t do that? 
And to get back to the Sears job, you would think that a job requiring more than everyday skills would pay a little better than that. Being competetive is important, but if you start having shitty service, you aren’t going to be competetive anyway.