[tarentel]

It depends on what your goals are. If you're doing it for fun or as a creative outlet this is great advice. If you're trying to actively get better you won't do it this way after a certain point. You need to be actively practicing and engaging your brain. It does matter what you play and how you play it.

[sanitycheck]

Sure, there's "deliberate practice" and it matters - but so many people seem to think if they're playing that's what they should be doing, or it's a waste of time. In reality that often isn't much fun, and they start to associate the instrument with this sort of difficult and often disappointing experience, and they give up.

[elevatortrim]

You are right.

I think there are quite a lot of people who are only interested in playing and never deliberately practising. They do not get that far (they do not have to!).

And then the vast majority of aspring guitar players who frequent learning online material (including me) spend all of their time practising and learning, and too little of it playing for fun and performing. Most are constantly frustrated about their progress.

Then there is a small group of people, who spend a lot of time playing for fun and performing, but also a good amount of time deliberately practising. In my experience, those tend to be the ones people think are great players.