I don't think people need to have a set path in mind but they should definitely have ideas and interests of potential careers, it's your job to help explore these. My parents never pushed me towards one specific career but helped open any doors they could and ensured I had lots of interests that could lead down different paths. While it didn't mean I left school to study something that was my ultimate career, it did mean I left with multiple areas of interest to explore, one of which ultimately is my role. Unfortunately the way you're going currently could lead to stagnation when they leave school or them missing out on getting a career they later enjoy. if there's literally nothing they could think about wanting to do, then you're not in a great place. There should at least be a lot of ideas.
There are so many options for them, have they ever tried any kind of work experience or shadowing? Have you ever taken them to see a court case, encouraged them to mentor younger students, let them try some art classes, taking them to visit castles, watched documentaries about the origin of the planet, gone to a nature sanctuary, done a science museum, written an article, watched Prime Minister's Questions, read literature, done a coding course, helped out in an office, anything like this? Does he enjoy being outside, is he sociable or does he prefer working alone, is he practical, does he like writing, does technology interest him? There are endless opportunities to engage with potential employers and sectors, they're always really keen to talk to the next generation.
All of these are ways to spark interests. Raise your bar a little higher for them, an apprenticeship is great if that's what they decide they want to do, likewise lots of paths through university. But it should be a CHOICE they make based on wanting to do it, not because their life has not prepared them to understand what is out there and they just need to pick an easy option. Kids who leave school with no enthusiasm for anything will have a lost 20s of doing work they don't enjoy with no path in life and without much likelihood of ever having a meaningful career.
The reason why students who don't know what they want to do in life take the uni route is that it's an opportunity to try a bit of everything, meet loads of employers and sectors, discover careers they have never heard of, all while gaining a degree that at least opens doors to some kind of job (if it's a decent degree).