Maybe we need a meta Q&A about whether the optional and expensive source books should be assumed when evaluating if a question is well-researched. i.e., can we fairly expect that all askers must first consult the rules text if the rules text requires them to purchase optional source books? In this case, is it fair to expect that everyone who asks
dnd-5e questions must purchase a copy of the DMG, Tasha's Guide, and all the other books?