Even I would suggest that my kids need the traditional classroom. None of this finish all your work within 2 hours and video games for the rest of the day. That can't be their educational days going forward.
When reading about your situation, it makes me wonder something a bit different. I guess it can be summed up with... why is it that your children normally go to school for six to seven hours a day for what should the same learning that they're currently completing within two hours? Is the work too easy? Is there not enough work? Is remote learning limiting the amount that can be taught, and consequently, the amount of work that can be assigned? Or are your kids too good for the current coursework?
Now, I do understand where you're coming from with wanting to ensure that they receive an adequate day's worth of education, and especially how two hours doesn't seem adequate. I've been around my girlfriend's children (10 and 13) a lot more lately, and my goodness... all the huffing and puffing, and whining about schoolwork is far more draining than helping with schoolwork. Although, I've also seen the quality of some of the coursework, and I haven't been very impressed. I recall this one Social Studies lesson that looked like a mish-mash of Wikipedia summaries with post-lesson activities that had questions that weren't even covered by any of the material (default or supplementary). There was also this one math lesson where it wasn't even clear if some of the concepts being used in the multi-answer question were ever covered.
It's ridiculous how much goes into the schools here - and yet, as I mentioned above, how much are the teachers actually doing for our kids? How much is even possible for a teacher to do? We can move to a mediocre district and still get the same level of education there if we go remote. No, I want the in-classroom attention for what we pay. And even if we aren't paying that amount, it is still the most effective for kids. The alternative, what we've seen in the last 3 months, is extremely ineffective as a whole.
I think the problem likely has to do more with class size and overall level of engagement. Ultimately, classes tend to involve a large number of children with varying levels of natural aptitude, willingness, and learning styles, and generally, only the far outliers get weeded out (e.g. gifted and special education). Even with the wide range that persists, teachers ultimately have to teach to some sort of average that can often leave higher performers (such as your kids) bored and without nearly as much to do. As an awkward anecdote, I remember one time in 5th grade when I was so bored that I actually asked for more math homework.
One thing that I try to push is relating things that we learn to actual real world situations. Back when I was younger, I was one of those kids that would ask "why?" a lot. I wasn't doing it to be a pain, but rather,
I wanted to understand. I kept hearing remarks about why they had to learn certain things. You know... the usual "we'll never use this!" sort of thing. So, I've been throwing out more real world problems and pointing out scenarios. Math is usually an easy one since we use it so much without realizing it. For example, one of the kids asked how many rolls they could have, and I just asked "How do they divide between us?"
Although, speaking of math and the quality of education, one thing that has made me raise a brow lately. I've been around my girlfriend's kids (10 and 13) a lot more lately, and I was taken aback when I watched them perform single-digit multiplication (e.g. 4 * 5) on their fingers. We had to memorize the times tables up to 10 x 10 back in third grade, and I went to a small school out in the boonies. I've also noticed a significant increase in difficulty when the kids approach an explicitly written problem (e.g. solve 4 * 5) versus a word problem. That worries me more given that solving word problems involves skills that transcend just math, and I'd argue that they're quite important.