Actually I would say lichees 2000 blitz is about
1800-1900 they are a bit tougher than 1700 and 2100 bullet is about 1900-2000 so I'm guessing 2000 bullet is about 1850-1900 ish in actual playing strength the higher the elo the more similar it is to chess.coms elo
Ex in rapid im 2180+ on lichess(I play more rapid there and about 2000 rapid on chess.com im around 2100 though I just haven't played enough in a while )
This is a great graph comparing this website ratins with lichess ratings and with OTB ratings. I have been playing chess on both websites for 3 years, I have checked ratings of most of my opponents in order to see the relation between their blitz and rapid rating and this website has data which is 100% inline with my 3 years of experience.
https://www.chessratingcomparison.com/graphs
Good info in that link.
A rating of 2000 in LiChess.org Blitz would equal 1754 in Chess.com Blitz, with an average variation of plus/minus of 115 points.
A rating of 2000 in LiChess.org Bullet would equal 1785 in Chess.com Bullet, with an average variation of plus/minus of 125 points.