I would bet money a judge would argue that inconsistent/arbitrary beliefs are in fact not "sincerely held" beliefs as defined under Title VII.
Also, SCOTUS made a ruling in 2023 that a business is allowed to take "undue hardship" into consideration for the company as a whole, meaning they can still fire (or not hire) you if your beliefs would be detrimental to the success of the business.
And the Dunning-Kruger effect also applies to "smart" people. You don't stop when you're estimating your ability correctly; as you learn more, you gain more awareness of your ignorance and continue being conservative with your self-estimates.
Though nothing about the Amish prohibits being a computer using engineer. Their rejection of technology is a lot more nuanced.