Yes, but apes on the whole are derived from monkeys; they and the old world monkeys are closer relatives than either is to the new world monkeys. Saying we evolved from monkeys isn’t so much wrong as missing a step.
It’s also not inherently stupid to ask why a primitive trait is still around. Because there are lots of cases where evolution does end up completely replacing older forms - the stem groups - and in some cases the reasons why or why not may be interesting.
For instance nearly all mammals today are viviparous; there were various egg-layers like multituberculates in the past that have all gone extinct. So it’s reasonable to suppose that live young are generally an advantage, and wonder if there is anything special about the platypuses and echidnas that has allowed them to hold out when all the other egg-laying mammals did not.
It’s just that in this case the answer is painfully obvious: there are still monkeys because they are better at, say, living in trees. So it might be a good question for a toddler, but if an adult still can’t figure it out, it’s probably because they haven’t really tried.
