In an ideal world, sure, but there can be times where it's better to just lock yourself out.

Maybe breaking out of your phone is just more self-control than you currently possess. Imagine trying to get in shape but you're only allowed to lift 200+ pound weights - you simply aren't strong enough to even make progress, you need an easier task.

Or maybe you just have other priorities in the short-term. I'd love to get to the point where I can easily ignore my phone, but right now my priority is to finish unpacking after a move and getting back into the rhythm of going to the gym. As James Clear says in Atomic Habits: To break out of a bad habit, make it invisible, unattractive, difficult, and unsatisfying. Locking a phone down to barebones functionality does all three.

Finally, maybe you have a deficit of attention. I've had diagnosed ADHD since I was a child - my level of self control for addicting systems is significantly diminished compared to a "normal" person. Yes, a certain level of this learned behavior: With dedicated effort and practice, I can develop that skill and get better about distractions. However, my baseline is still lower and my progress will be slower than a neurotypical person. Crutches like this help me preserve mental energy for my day-to-day tasks instead of spending a significant portion of my mental energy fighting the urge to check my phone all day every day.

Just my perspective at least. I know everyone is different and I aspire to be the kind of person that doesn't need to employ blockers and safeguards just to ensure I don't end up getting sucked into doomscrolling for 2 hours, but right now I'm working with what I've got.

A good analogy is if you've ever tried to eat healthier and cut out most junk food from your diet. If you're anything like me, that is a LOT easier if you don't have a sleeve of oreos in the fridge and a quart of ice cream in the freezer, at least at first. Maybe after months and months of dedicated dieting, you can allow yourself to indulge in 1-2 cookies after dinner, but when you're first getting started, a cold turkey approach can be much easier, as you have to exercise a lot less willpower if the temptation isn't readily at hand.

Appreciate the perspective. I can see how it would help someone with ADHD.

For me it's a bit different: It's phases.

Some phases of extreme self-control, others where I tend to give in a bit more (usually induced by external stress).

But that tells me I have it in me to do it without external fences.