I do think explanations are important as kids get older - it’s part of the asking “why” about everything stage that helps them find out how things work. So things like why we brush our teeth, why we have to have a bath or not be mean to people etc do have explanations. But ideally a child is asking about those things after they’ve already become habit from being reinforced from babyhood. A very small child should for example just be getting their teeth brushed even if they don’t like it, using distractions etc until you can get to the explaining stage. Not waiting for the explaining to convince them.
I don’t think boundaries and rules just help you to not be an entitled snowflake as you get older. It’s also about a sense of solidity and that you grew up surrounded by a firm framework - that your parent/s was/were in charge and you could rely on them knowing best (not 1000% perfectly of course but for the basics). Yes kids kick against that and it gets relaxed as they get older, but it’s there to kick and push against so they can work through that and be shaped by those experiences.
it’s like a sapling growing in soil with stakes, it gives support and allows the sapling to get taller and stronger, then it gradually grows its own strength. No boundaries is like no soil and no stakes, the sapling will just flop around and not be able to grow strong or in the right direction. Hmm maybe that’s not perfect but to me it’s not just about controlling behaviour. It’s about providing a clear “container” that a person can grow up and out of.
Re homework, I think it’s very discriminatory and should be optional. I have one older DC who was totally self-motivated and sailed through always doing homework with no bother, and another who has multiple SEN - getting her to do homework is a total nightmare and basically it doesn’t happen because getting through a day of school completely exhausts her and she needs downtime to be able to unwind and get to sleep, which affects being able to get into school the next day - and doing the homework takes her way longer than average so uses up all her time. School are understanding fortunately, but homework discriminates against kids who are struggling academically or mentally, who have a chaotic home, no space of their own. other responsibilities at home, parents who can’t help because they have to work all hours, etc.
Another thing that bugs me as well is that if your child does have SEN or MH problems or other issues, they are often assumed to be ill-disciplined snowflakes who have never been told no, because that does happen a lot. So you’re sitting there explaining to school/CAMHS/etc that yes, you do have boundaries and brought your child up hearing the word no and with clear consequences etc because their first assumption is that you didn’t.