Easier in a bull market, than a bear. If prices are rising, you can selectively pick players to cash in on, and meet your above income deficit.
If reduction in current value exceeds amortisation book value, and/or nobody is buying. Then you have a problem.
But it will be big clubs that have, so the rules will be changed.
Football is a self inflated bubble, chelski, manshitty, now Saudi, have pushed prices up artificially (and intentionally to push out of competition those who can't compete financially), out of step with income.
Winners and losers in the financial sphere rely on entropy in the system. If the cash spreads out to the same financial level across all leagues and clubs, nobody has an advantage. That's a death to the monetization of football. So there is a constant injection of energy from the entitled controlling sources to ensure that entropy remains.
Expanded European football, super leagues, dirty/immoral money, all are inevitable to promote continued entropy, or the system collapses.
Remember, you are watching a money game. The football is just the medium that they are creating their art on.