This probably won't be a popular opinion, but for all the complaints about billionaire Sheikhs and Russians (which are in some cases justified), you can't deny that we as a football club were also lucky to be in the right place at the right time to benefit from the formation of the Premiership (in fact we were one of a select number of clubs pushing for the Premier League to breakaway from the Football League).
Moreover, the very fact that we are located in London, one of richest regions in the UK, and that we are particularly popular amongst the North London/Home Counties affluent middle classes (thanks in part to Nick Hornby's book) means that our revenue generating potential is much greater than, for example, certain teams in the industrial North/Midlands, which have been decimated by factory closures as the UK economy specialised in Services rather than manufacturing (and obviously the South East benefited enormously from that).
All this means is that the only way for other clubs to break through the oligopoly at the top of the Premiership is by getting bought by a foreign billionaire who can pump a lot of money into the club. They can't do it organically, and given the revenues that can be gained from UCL qualification, there's a feedback loop that simply entrenches our position at the top (we qualify for the UCL, gain the revenues, which increases the gap between us and the rest, making it more likely that we can continue to qualify for the UCL, and so on and so forth).
Sometimes it easy to forget the enormous advantages that we as a club have been blessed with when bemoaning the "luck" of others who happen to have been taken over by a rich businessman, but we as a club have not been passive bystanders in this play. We have been active participants, and our own greed back in the early 90s helped set the wheels in motion and has come back to bite us in the arse.