Football mirrors society in that the extent to which the rich get richer and the poor get poorer has grown in the past thirty years (particularly in the Uk). That said, using the Championship as an example, there have been just four examples of matches with a winning margin of three goals or more with the campaign now just about a month old - that figure would always be far higher during the times when it’s claimed there was a more level playing field.
To a degree, the Championship is still a division where you can do well on a small budget - Leicester apart that’s no longer true in the Premier League and hasn’t been since its inception. The biggest clubs are now so powerful that any attempt to “clip their wings” by the authorities would probably fail, so I don’t see the current position changing unless there’s another attempt to form a Super League which succeeds.