I haven't been doing it as much in the winter, but I find that jar salads are great. I can pack 8 salads (lunch for 2 for a week, allowing for a day of leftovers) in about 30 minutes. That is usually 2 types os salad. I use the same greens with different additives and dressing just to have more variety. Lunch for the whole week, for 2, in about half an hour. Tha is with the proteins which are usually some combo of hardboiled eggs, chicken, ham or other cured meats, ready to go. Some of those do take more time if you aren't using leftover or just adding another chicken breast to a dinner you are making, but buying lunch meats or salami eliminates that if one is looking to be most efficient.
And much like the prepackaged salads I posted above, there are shortcuts like pre-shedded cheese, hardboiled eggs bought already cooked, shredded greens instead of heads, etc. Those all increase costs, but would still end up far below $15 per lunch! I've never bothered to price mine out though.
And none of this requires cooking skills. You throw dressing, some toppings (shredded carrots, sliced cucumbers, shredded cheese, feta, corn, whatever...) protein, and greens in a mason jar. So you aren't even dirtying multiple containers or carrying more than 1 item to work. You need to keep it mostly upright, then shake and either pour into a bowl or eat from the jar.
The problem with this is a lack of understanding, and just generally being intimidated by the kitchen. And I understand that. I find cooking scary and stressful and my initial reaction to any new recipe or process is usually, "I probably can't do that", which is something I'm aware of and have to actively talk myself out of, again and again. So for someone who is intimidated by just about anything that happens in the kitchen outside of sex on the counters, "make salad" probably seems like they'd be out of their depth, particularly if they are looking for an excuse to just continue doing what they have been, rather than moving outside their comfort zone. And even more so if they have some sense that cooking isn't "manly", and therefore isn't for them.