It's confusing to use the hypothetical of 100% in one sentence and in the next acknowledge that the optimal rate of taxation for maximising revenues is not at 1

It's confusing to use the hypothetical of 100% in one sentence and in the next acknowledge that the optimal rate of taxation for maximising revenues is not at 100%. The question is whether tax revenues could be raised by raising tax rates to the point that revenues exceeded current expenditure. Whether or not that is possible is uncertain.