Can you explain what do you mean by that? It is quite rare to see broken trrs jack on a laptop, at least I have never experienced one, nor on walkman or anything getting heavy plug/unplug use.
I thought it is an issue in reducing the cost to manufacture the case or something.
So yeah, they break, but they are (or used to be?) quite cheap to fix (and this was one of the super thin 13" xps)
I had a slim XPS13 and IIRC the headphone jack was on it's own little board. That makes it quick/easy/cheap to repair if you know what you're doing / have the service manual / are comfortable taking it apart.
Not all things are designed that way; sometimes the jack is right on the main board and most people that buy dell laptops are not going to DIY through ali express; they're going to use up phone support time, require a shipping label, technician time ... etc.
You take care of your hardware, even during "heavy use," many people absolutely do not - and are downright abusive.
Many of these parts exhibit partial or intermittent failure modes where it's more expensive and difficult to determine warranty eligibility than to just fix the problem. Peanut butter in the jack, loose solder joints, whatever.
Doesn't this make including the jack even less justifiable?
Framework laptops have another decent strategy, where you've got on-motherboard ports that have relatively few usage cycles, and are protected from most forces because the easily-replaceable custom-dongle-squares are held in place quite securely. They take the damage, protecting the motherboard. And as long as the motherboard ports are still good, you can even forego the modular thing and just plug in directly if needed.
Furthermore, the warranty determination isn't free, either: in addition to the repair itself, some (likely multiple) employee's time was spent determining whether or not an issue existed at all, whether or not the issue was covered, whether it could be fixed, and facilitating the whole transaction.
Repairs also don't result in 100% yield. Depending on your company policy you might be eating the whole unit because of a mishap or just plain stubborn components/physical realities.
Repair fees don't cover all of the organizational moving parts required to actually carry out repairs.