There is a skilled player in Honkai Star Rail who beat the Elite Four using a level 20 Linoone. 99.99% of players don't even consider that option. If that's not mastery, I don't know what is.
A few funny examples of skilled HSR players using low rarity characters to beat the hardest content. Copying them and doing the same thing is not mastery. Mastery is learning how to do it. Even with the same gear, I doubt many people would be able to play this team to achieve the same results (example: 4-star team run).
Mastery in Honkai Star Rail is really about understanding your team and how to use every character to their fullest even low rarity ones. Beating tough content with a level 20 Linoone or a 4-star team shows skill beyond just copying builds. To keep your team strong and ready you need resources which can take forever to grind. Using an HSR top up is a smart way to get Stellar Jades quickly so you can upgrade your gear and characters without wasting hours. It’s fast simple and helps you focus on strategy not farming. Definitely a good move if you want to stay competitive without burnout.