I completely disagree. Do not rely on ancient texts to give you understanding of what mathematics is about. They're very difficult to read, they do not teach well, and you'll know next to nothing about even basic notions of mathematics, as understood now, after you're through with them.
Do read the classical texts for pleasure, to round out your education, or to understand the history of mathematics. But don't study math from them, that'd be a terrible mistake.
I'd be curious to know what you find difficult about them, and why you think they do not teach well.
I find Euclid extraordinarily clear in his exposition of geometry. And I have not yet found a better teacher on conics than Appolonius, although Descartes comes very close with his analytic geometry.
Are there some defective constructions in the Conic Sections or in the Elements that lead you to say that "you'll know next to nothing about even basic notions of mathematics"?
It's not clear to me why you think that the ancient texts are lacking in pedagogical power, except for perhaps a personal aesthetic preference.
Do read the classical texts for pleasure, to round out your education, or to understand the history of mathematics. But don't study math from them, that'd be a terrible mistake.