Disclaimer 1: Not a lawyer. No legal experience whatsoever.
Disclaimer 2: If a current or previous employer sees this, I'm impressed you found this account and linked it to me for one, but I'm not disparaging any of you guys or calling you out by name so please don't sue me. I don't have any money worth taking.
I had a conversation with a friend about this in the past. Believe it or not, you'll see these kind of non-compete clauses in retail, fast food, grocery, and warehouse work too. They're not really meant for the entry level employees, but they're part of the standard HR paperwork that everyone has to sign, so everyone is beholden to that policy. Technically speaking, from what I understand, for a lot of people that part of the contract would be deemed unenforceable because they do not have any skills or knowledge that's exclusive to the company and it doesn't take a lot of training or a lot of money to teach someone how to load boxes on a pallet. Most people in low skill, entry level jobs can go from one company to another and not have to worry about the non-compete clause because these companies have bigger things to worry about than someone who makes $10 an hour. However, some people do hold back, just in case, because if you make $10 an hour, there's no fucking way you can afford a lawsuit.
You'd be amazed at the stuff that even entry level workers have to sign that dictate things such as whether or not they can take a second job in a similar role, what they can and can't say on social media, whether or not they're allowed to talk to the media about their work experiences, and on and on. You'll often find policies that run counter to the FLSA, FMLA, and other acts that would then be by default unenforceable, but once again, can you afford the risk of running counter to those policies and losing your job? Doubly so if you're not in an union and are working in an at will state? I know I can't. Shit's scary as fuck.
Still. Employment laws change all the time from the county to the federal level and it can be hard for HR Teams to keep up. Hence, boilerplate and sometimes dated policy contracts. I'm not excusing anything, just adding a bit of texture to the story here.