I think one naturally thinks that "Constraints on effective altruism" concern some principled or otherwise permanent constraints on effective altruism (cf. moral side-constraints), but actually this article rather seems to concern temporary bottlenecks, such as funding, talent, or vetting.
Alternatives could be "Constraints within the effective altruism community" or "Constraints within effective altruism" ("Constraints in effective altruism" is another possibility - I see now that Pablo mentioned that). Or one could try to find an alternative term to "constraints" - maybe there is a term, e.g. in economics.
80,000 Hours has previously stated that it believes that, within the effective altruism community, talent constraints are more pressing than funding constraints (Todd 2015). This happens primarily because the effective altruism community has access to large amounts of funding from members of this community pursuing earning to give as well as external philanthropists.
And I also added some text on 80k's more recent writings/discussion of various misconceptions related to "talent gaps" and why something other than "talent" or funding constraints might be the main constraint in EA nowadays.
I also made other small tweaks in light of 80k's more recent writing/thinking. E.g., I removed "80,000 Hours’ overview of why talent constraints might be more important than funding constraints" from below one of the sources, since I don't think 80k would want readers to see that simplified line without reading the full piece or reading their more recent work on the topic.