At the top of the game, the spending far outweighs the income, but it's possible to compete purely on the Sky income if you're willing to work within those constraints. Burnley did it for years, even building state of the art training facilities at the same time (though their new owner has now loaded them with debt), West Brom the same, also Sheffield United recently. There tends to be a fair bit of yo-yoing if your operating that way, but I doubt any of us would have an issue with that.
More have failed than succeeded. The league is billions in debt. Burnley are hardly the norm are they? And arent we in the same league as Sheff U and WBA this year? Hardly shining examples of top-flight sustainability.