You could make a case. Depends whether you count two European Cups and many more trophies this century as being "bigger" than more sustained success and many more domestic honours in total but no European Cup.
I don't, personally, but it's hardly West Brom singing "pride of the Midlands" levels of delusion.
Again, I don't agree, but there will be plenty of people worldwide who genuinely think Chelsea are the bigger club.