Why can I go against and fight champs in emerald?

Hi so I was wondering about something and had a question, I played siege for about 2 years and hit emerald 2 at my highest with a good k/d averaging around 1.2 and 1.1 I play shields some seasons thats why it fluctuates one season ill play all shields the next ill play all guns,

but ive been going against champions sometimes and ive beaten them, sometimes i lost other times ive won against someone who's been diamond for years and champ, im kinda sad cause i had a goal to reach champion and it never happened i feel like a loser but at the same time ive beaten champion players and been in champ lobbies and held my own....

I feel like im not good enough to be champ and doubt my skill but then I beat champs and get confused and I look up their stats and they have like high k/d sometimes and im like whats going on? Why is an emerald player (me) beating a champ? And im like why am I in champ lobbies? Ill forever be stuck emerald if im stuck in champ lobbies, and my teammates are hardly good they are always like have no clue whats going on, it feels like a 1v5 every game..

So like im so confused am I dog shit or not? My goal was to reach champ and prove to myself I could do it but im already going against champs just without the title...so im super confused....

If anyone could help and end my suffering id really appreciate it lmao...

Im also doubting myself like "did i really gp against champs or is that false memory? Cause there is no way I can beat them as an emerald player right?"

Lmk and thanks so much lmao...