At some point, kids have to develop the discipline to do the things they need to do, whether they want to or not. Carrots are better than sticks, but in the real world there are a lot more sticks than carrots.
I was a passionate and interested kid. I had a lot of boring classes in high school, but I worked hard at them anyway, even when I didn't give a shit. I got good grades because I knew bad grades could jeopardize my future. That was my stick; kids who don't take that seriously might need a different one, but ultimately you can't keep them going with carrots forever. It's good if they can be intrinsically motivated, but kids often will not be, and they need to do things anyway.
Some families will decide to push harder, A's and AP classes are required, full effort in academics at all times. Some families will decide every assignment has to be completed and A's and B's with maybe an occasional C in a very hard class is acceptable and the student is left some bandwidth for social/non-academics. Some families take a simple pass/fail, as long as the kid finds a way to pass then they are good. So on...
The throughline is the parents are involved and monitoring the whole school year. Is homework being completed, how are your grades, talk to teachers when needed, etc. I feel this basic parenting is no longer common, parents want to blame the education system without taking any responsibility.
Sure we can incrementally improve education along the way, but we have to have a good faith expectation and base line of participation as a foundation or nothing will work.
Kids lose their curiosity because they witness their peers goofing around and not taking it serious. So if my friend's parents don't care and he's allowed to goof around instead of putting in the work, then I get a sense of FOMO or feel like a sucker for putting in the work. So everything devolves to the lowest common denominator. There's a lot more group dynamics and kids obviously don't know what is best for them, so adults really need to tell them what is expected. It's amazing how quickly a class elevates when you remove 1-2 distractions and likewise when the whole class is engaged and there is no distraction to begin with, it's ideal.