If a Hausdorff space $\ X\ $ admits a dense subset $ A \hookrightarrow X\ $ such that
$$|X|^{|A|}\ =\ |X|$$
then indeed $$|X| \leq |\text{End}_{\text{Top}}(X)| \leq |X|^{|A|}\ = \ |X|.$$
It is the case of $\mathbb{Q} \hookrightarrow \mathbb{R}$. Thus, if there is a small enough dense subspace, there are not so many endomorphisms.
Is the converse true?
Namely, suppose $|\text{End}_{\text{Top}}(X)| = \ |X|.$ Is it true that there exists a dense subset $A$ such that $|X|^{|A|}\ =\ |X|$?
This question generated some attention on MSE, but it did not receive any answer, thus I am reposting it here.