Lifestyle choices are crucial, but when your environment is saturated with bad options that are cheap, convenient, and enjoyable, its often hard to stick to those lifestyle choices.

It is hard. Taking control of your instinctual thoughts and overriding your impulses can take a long time, sometimes years. And like you say, the issue is compounded by the fact that apps are intrinsically designed to be addictive.

But those things are a given. Whilst you can't ignore them as powerful factors, I feel a lot of people allow themselves to use it as an excuse to not face themselves down and make the consistent, difficult choices. They allow it take away their agency and succumb to a self-fulfilling prophecy. "Oh well, I'd like to stop but I can't because it's designed to be addictive". Yeah, well you're just going to have to try harder then.

Regardless of how insidious smartphones and their apps become, you still have a choice. Pick up the phone or don't. Open the app or don't. You know you have these choices. One path will make you feel momentarily good but ultimately bad, the other path the inverse of that. You will succumb to the temptation often. But over time, you will start to make the difficult but ultimately desirable choice more often. In turn, you'll develop the circuitry in your brain for it to become your default behavior.

The way the majority of apps are designed is not going to change any time soon and you can't control that, but you can change.

I think it can be analogous to learning a piece on an musical instrument. You start painfully slow and fuck up every second note. Just as you're thinking that you've got a handle on one part, you focus on a different aspect and lose it again. But gradually, over many days/months, your brain adapts and reprograms itself. Until, one day, you can play the piece effortlessly.

Or, instead of bettering yourself, you can lock your phone in a box, put your fingers in your ears and go: "la, la, la, I can't hear you". And nothing will change.