The short answer is yes, they did. Next preview please. The money brought in by Roman Abramovich when he purchased Chelsea indubitably changed the way football was financed moreso than the manner in which it was played. Now, as before, the better team generally will win on the day – through better players, tactics, preparation or execution; occasionally the second-best side wins more through good luck than any particular skill, toughness or nous.
That Abramovich himself funded the club is more the changing factor. Deep pockets are nothing new, it's just in the past those pockets were lined through sponsorship, winning and full-to-bursting stadiums. Manchester United has the single largest home stadium in Britain in Old Trafford and are able to fill that stadium months in advance right to capacity. They've done so since the 1970s or even before and Liverpool were consistently the welathiest clubs by virtue of their fans, stadia and sponsorship deals. Those things deepened a club's pockets, not so much a benefactor in the style of our Roman.
Abramovich's legacy to football as a whole was to personally follow the Real Madrid model: a club hocks itself into enormous levels of debt to fund player transfers and enormous wages. Rather than owing other creditors, Abramovich forked out himself and the majority of the club's debts now were to him and were subsequently cancelled. (NB. I don't think cancellation was the original idea). He's essentially personally funded a crusade to fill Chelsea's trophy case and then cancelled the debt in a bizarre parody of the “Make Poverty History” campaign.
By spending money on both Claudio Ranieri's and Jose Mourinho's squads, Abramovich has taken Chelsea to the top of British football, and nearly to the summit of European competition. One man had never before brought about such a sharp rise in a club's fortunes and so one can say he's changes the world game. I guess because he's changed the world game he has in some manner changed the world, though whether it's for the greater good is questionable in the extreme. That he's begat a bunch of followers who have stated similar aims (Sacha Gaydamak and most notably the Manchester City consortium) is another indicator he's been successful in his spending with the side effect of transfer prices accelerating beyond all control over the last five years and that there now is a stark divide between the “haves” and the “have-nots”. The “haves” spend money freely in a tight economy, where the “have-nots” focus on developing youth systems and top-up signings. In essence, it's simply a more bipolar example of the past paradigm, the difference being there are only two “haves” (Chelsea and Man City) with even former big spenders Liverpool, Manchester United and Arsenal are being conspicuous with their cash.
Congratulations Roman Abramovich. Single-handedly you've changed the world.