It'll make you good when they stop walking into charged smash attacks.
I think they programmed it so that the AI does stupid things sometimes so that you have an actual chance of beating them.
Unfortunately, most people who are good at the game don't just walk into charged attacks (not just Smash Attacks, they'll just walk into stuff like Flare Blade too).
A better way to have programmed it would be that sometimes, the AI miscalculates the range of their attacks or blocks/dodges at the wrong times.
The way it is now, the AI will just go into a sequence of... doing nothing for no reason, or running away for no reason, and other things like that.
To get good, you have to get good and learn the techs.
Beefy Smash Doods is a very good channel to help you with Smash Ultimate.
Speaking of "techs", I need to learn how to tech.
I also need to get better at off-stage play, since that's my biggest weakness (basically, I'm Little Mac, I ain't no air fighter).