I honestly think a lot of this is societal expectations that have developed very quickly since Covid. It no longer seems like an expectation that students (or anyone for that matter) should work hard. A few things that have worked for my program...

I try to give my students resources to help them practice more efficiently and effectively so they actually feel like practicing helps them. It doesn't work for every kid, but I do think it has helped the ones that want to improve.

Another thing that has helped my kiddos is reminding them that "5 minutes of practice is better than no minutes." Some kids don't realize that it doesn't have to be an hour long practice session to matter.

This really helped my baby band, but we had a long discussion about why they chose to stay in band - and I included the fact that many people stay in band for the social opportunities (and that's ok), but I also told them that if they have any interest in improving then they have to put forward the effort. We also took the time to make goals (what do they want to get better at in the next month, in the next two months, etc.) and created a practice schedule that they felt was realistic for them. I told them it wasn't about the amount of time on their practice schedule, but rather how much of the time they could actually hold themselves to.

Again, doesn't necessarily work for every kid, but I think we just have to teach them how to want to be better these days, sometimes.

You may have tried all of these things already - but I hope something help spawns an idea that will help your group! Don't give up!