They're not mutually exclusive.
There's nothing above to say that I'll forego practice, just because I have a smoother trigger in play.
No, but a lot of people think they can forego the former by simply spending the money for the latter, and will be a better shooter because of it.
The point here is to be able to pick up pretty much any box stock gun, and be able to shoot it well, which really isnt at all hard. "If", youre accustomed to shooting box stock guns, everything is easy.
The reverse isnt usually the case, and hence the booming business in aftermarket triggers and gunsmith work.
What Ive come to find is, the more you practice with and use what you have, the better the trigger, action, whatever, seems to become, assuming youre even paying attention to them (I generally dont). Its not the gun thats getting better.
The biggest reason people who dont shoot DAO have trouble with it, is because they dont have the muscle tone and related experience to do so, because they "dont" do so.
Same goes for pretty much any other shooting discipline, once you step away from a bench, and you and the gun, have to shoot as one.
Shoot a box stock DA trigger DAO daily in dry fire and practice for a month, and at the end of that month, you will find that trigger will be great. As good or better than a tuned trigger.
Funny thing is, nothing has really changed with that trigger.