It would be great if this question could be in the FAQ because doesn't it come up literally every day? Not the 1900 part, but the whole ratings issue and people wanting to either get opinions or flex their new ratings.
I suppose to a 1500 a 1900 is a good player, and almost unbeatable. Now to a 2400 player a 1900 is crushed over and over.
Two 1900 players going head to head, would think perhaps, "how would we do against a 1900 player on another chess website like
chess.com or chess24"?
" I am really tall and good looking, do you think that girls like that, or would it be better if I was shorter with less gorgeous hair and small muscles, without a job?".
Okay, I'll attempt to not be so snarky, and break this down. Let's all beat this dead horsey into the dirt.
Lichess is one of the largest chess sites in the world. It's either 1 or 2, so there is a large population of players. The rating system they use is arguably the most accurate. However, other sites might use the antiquated ELO rating system because it is still used by FIDE, I suppose. Do your own research, is the short answer.
Now, I'd like to go off on a tangent about what the heck is FIDE and how does someone get into this organization, but that is a mystery, and you probably have to be a prince or a president of a country, and there is a secret ceremony and blood oaths and such.
If I'm the president of FIDE do you think I would have a high chess rating? Is a forum question, I suppose.
Do you think it is easier to be the president of FIDE or the Olympics or FIFA?
If all the 1900 players in the world from every website had a tournament and it was won by a player from
chess.com, then that would settle it?
Then there is the question, "a 1900 under what time controls or variants"?
It's hard not to be snarky, is the answer.
The captcha was a variation of a David and Goliath Mate.