both and neither. in some programming languages I'm barely literate, like I know enough to cook a php landing page or a simple file/database accessing system should the need arise for something simple, cheap and done yesterday. in some like Java I take pride in knowing them far beyond what's required on the job and in being a reference point for my team. some stuff like node.js I just put my hand into because I can get around, but hatee it with passion and will only do if strictly necessary.

so the question is what drives my choices? for one I can derive a lot of wealth out of my knowledge. on the other hand there's the pride of accomplishment.

but if I had to generalize I say lot of people around me just have an utilitarian approach to knowledge, and they won't deepen their unless enticed or coerced.

beside I can't see people getting around and just learn stuff outside what's in their interest to begin with, me included, didn't and won't care to learn ancient languages and those lesson at school were just a chore

note that I think of it heading also has another purpose, to let parents know efficiently if these any hiccup in some courses. how held would parents know where their kid needs help? sure there's the semestral parent-teacher meeting but that seems inefficient and too coarse compared to punctual grading

Both, I think but it depends on the situation. For many things in life competency is enough (although there are still tests involved in demonstrating this) but there aren't unlimited jobs in any field so being 'better' certainly makes you more desirable. A racing car driver is measurably better than me at driving but then driving is not a job for me and so proficiency alone is acceptable.

If you want to use these skills not only for yourself, but to sell them to others as well (as labor), it's really helpful to know where you stand on the market. Otherwise you might think you're good enough at something, devote a lot of time to it, but only later learn that others are better at it.

In fact, I think it's quite common scenario in a lot of solitary pursuits, be it intellectual or artistic. Without the immediate ability to compare, you can spend years doing something without being rewarded for it at the end - for example, Hitler spend a decade trying to be a painter, before he finally owned his failure and switched to politics. If there was a way to get reliable feedback in painting without putting a decade of work into it, he might've had abandoned it much earlier and not grow his resentment towards "the gatekeeping Jews".