PSO2, Like all RPGS, and pretty much all games in general, requires the player to put in the effort and time in order to get those high-end equipment that he has.
You are clearly in the right direction if you are inspired by what your friend has and the things that he can do, if you put the effort in and with proper guidance, you also can accomplish it. there are many people willing to help, but in the end, it comes down to you wanting it. think of it like something you want IRL, you want it? you gotta work for it, make the money for it, and get it, simple as that. you can always settle with Affordable gear (which there is nothing wrong with that), but if you want what some of us call "Big dick" gear, A LOT of effort must be put in must be put in to acquire it.
As far as the skill comes in, this comes naturally over time with proper guidance, and practice. practice. practice. learn your class, learn its ups, its downs. pay attention to enemy move patterns. every single boss in this game does something that will let you know what will happen, and it will never change. it all comes to practice, and as a good friend told me once, its called personal growth.
I'm not going to tell you to quit now, if you are making a thread here, its because clearly you want to keep playing, but you gotta be hungry for those things and put the work for them, as with any game pretty much putting in the effort to reach "endgame. PSO2 is really a game that there really is no endgame. the endgame is really what you want to make it. dont give up. get up, learn from your mistakes, and keep going. that's the only way you will become a GOAT.