2000+ players are generally great at tactics with decent opening and endgame knowledge. The biggest difference I've seen over 20+ years of competing is with 2200+ players having a much greater understanding of positional play and activity. Find a good book on it, the Zurich '53 one by Bronstein is a good one
How do I get past 2100? Really Important!

you guys get consistent openings 😂
lucky...
Bro we ain't lucky. Just to avoid stupid mainline which require so much memorization, I play dumb openings to get out of theory

thats why you cant get past 2100
you play dubious bad openings and people can punish them
Its not exactly bad. I just drew a GM with the modern so I'm sure it isn't that bad. I just don't want to get into mainline theory because the opponent knows what to do. Instead, I want them to get into my theory where they feel uncomfortable.
you guys get consistent openings 😂
lucky...