I agree with you @InvincibleDB10
It's very subjective unless the exact yardsticks are defined, but for me Chelsea were no bigger than West Ham in the 90s
Back then the domestic support base was more telling of how big a club is. Now it's all a bit murkier as the English Premiiiiiiier League is basically a global competition that merely happens to be played on English soil.
Tottenham have traditionally been a bigger club than Chelsea, really not sure how that could be argued against. I guess they overtook them at some undefined point in the 2000s, with Abramovich being key to it, altho they did enjoy more Cup success than the scum in the years prior to that.
Arsenal are a different kettle of fish, but assuming Chelsea win a few more league titles before we get near our next one, as the years roll by you'd have to say they're getting close to our size now. N00b fans would say already bigger of course
History and heritage IS important with a club, success is success but with the chavs it's all recent and until its sustained over a bit longer time period they won't be seen in the same light as traditional big clubs.