I think this is a bit of an overstatement. In my experience — I'm an athiest who doesn't follow any particular religious rules either, but I was raised Orthodox Jewish — most Orthodox Jews do truly believe in God, and believe that at some level they'll be punished for breaking the rules and rewarded for following them. It's true that teenagers who haven't yet left home might be going through the motions cynically — when I was in high school, I was — but that's generally not true of adults: if you don't believe, when you leave home (either for college in the US, or army in Israel), it's fairly easy to "fall off the derech" and stop practicing now that you're free to find your own community. That might not be true in some of the ultra-Orthodox communities in Israel that are exempt from army service, or the Yiddish-speaking communities in America where there's a language barrier preventing you from interacting with the rest of the world, but for most religious Jews there's a pretty strong element of true belief. Religious Jews are a pretty tiny minority in the world; if you don't believe, it's pretty easy to find something else to believe in or to have a community around.

> I think about it like following requirements set by certain certifications. Not all requirements make sense in every context - sometimes you may feel silly complying, knowing you're doing it just to check a box, even though there's no practical value to it. But there is a value to passing the audit and getting the certificate saying you comply from EY or whoever, so you abide by the requirements, even when they don't make sense, so you can show your ~Kosher~ ISO certificate when you need to.

In general there are a huge swaths of rules in Judaism that are expected even within Orthodox Judaism to serve no practical purpose, other than simply God (supposedly) said to follow them. If you believe that God said you can eat a goose, but you cannot eat a stork, why is it any more ridiculous to believe God said you must not light a fire on Shabbat? It's all kind of silly unless you believe in the fundamental premise that these are rules from God, in which case none of it is silly. In the Orthodox communities I was raised in, the idea of a checkbox that you feel silly complying with didn't really exist: either you believed in the premise that God really wanted you to check those checkboxes, or you didn't, at which point why were you not eating shellfish or driving on Shabbat?

There are social norms too, of course. But at least for religious adults, in my experience it's mostly uncynical.