Income is easier to calculate, but wouldn't "total net worth" be more fair? An ultra rich person might show no income for a year and pay no taxes, because they

Income is easier to calculate, but wouldn't "total net worth" be more fair? An ultra rich person might show no income for a year and pay no taxes, because they lost a small fraction of their wealth, whereas an ultra poor person who has a lucky year and makes the median income once will be taxed even though keeping extra cash in their pocket would probably be the best possible use for the money.