Honestly, "advice" like this made my own self-image being shit for decades until I was diagnosed with ADHD and started to understand how it works. I guess that works wonders for some people. But that's their thing and trying to tell others that's how you do it if you don't want to be lazy is just making people feel broken when they can't do the same thing
Why is doing homework hard to begin with? For me, it's because my brain absorbs dopamine at a much faster rate than a neurotypical brain does, and my brain is a junkie always looking for its next fix. Which homework doesn't even come close to providing. You can come up with all the systems and self-hacks you want, but if they don't make homework be something that gives me a dopamine kick, I'll always have issues getting to do it. It doesn't even matter if I know that not doing X now is going to make things way harder for me later. It's a physical, biological problem, not an "attitude" one.
It's like telling someone who is short-sighted they can sit in the back of the class, they just need to have a system, or ask themselves why it's so hard to see the board. No, they need glasses or sit in the front row, and no system is going to change that.
What it works _for me_? Listening to music. Or a podcast. Having something on screen as a background. Walk around while I study. Basically, finding things that part of my brain can do to get its fun kick, while still leaving some bandwidth to do the not-enjoyable thing at the same time.
But that's me. And not all the time. I got to my own strategies after decades of trying and failing all the normie advice and strategies (I had sooooo many planners with just two days worth of usage... ).
What I'm trying to say is that if you are someone for whom struggling with doing things society demands you to do is a recurrent problem, don't listen to anyone telling you that "you just need to...".
You need to try stuff. Find what works for you. Sometimes, maybe you need to study while you play videogames. Maybe you need to run 2km so you have 15 minutes of focused attention after. Maybe you need to study, or do your taxes, while taking a bath. Maybe you need to sit alone in the forest. Maybe your focus window only triggers from 1am to 2am.
So for our baby ADHDers on this site who still struggle with The Shit: don't try to follow this kind of advice. Or better, try, but be quick moving over if it doesn't work for you and just try to figure out how the happy drugs factory inside your brain works so you can trick it to start working when you need it. Sometimes. Because we are not neurotypicals, and that means there is not a pattern that is going to work for most of us.