Why has my question What is the etymology of "baca" and "baja", which seem to be antonyms with a single letter of difference? been marked as off-topic? I have to discuss something about the two words "baca" and "baja". I tried searching on Google: https://www.google.com/search?q=spanish+%22baca%22+%2B+%22baja%22&oq=S&aqs=chrome.1.69i60j69i59j69i57j69i59j69i60l3j69i65.1968j0j7&sourceid=chrome&ie=UTF-8 But, I did not get any good results. When I do not find any good results on Google regarding a topic, I decide to post a discussion on StackExchange. Currently, I do not know any other sites to post discussions.
Questions about etymology are, of course, welcome on the site. As I am sure you have found out as a long time user of the site the source most people use is the dictionary of the Spanish Royal Academy https://dle.rae.es/?w=diccionario. This gives the etymology of each word, where it is known. So with a few clicks you could have discovered the etymology of both words. I cannot speak for the close voters but it seems to me that the view was that it showed lack of research effort.
Your Google search of
spanish "baca" + "baja"
is of course not going to bring any results about etymology.
Second, the words "baca" and "baja" are completely unrelated, so your question asks two questions in one, which is also frowned upon on Stack Exchange. True, the two words differ in only one letter, but there are tens of words that differ in only one letter from "baca", such as "bata", "bala", "baba", "caca", "daca", "faca", "haca", "laca", "jaca", "maca", "paca", "saca", "vaca", "beca", "boca". So you could also ask why "baca" and "boca" have different meanings. Or why "baca" and "saca" have different meanings. But the answer would always be "because they are different words". As flooding the site with such questions would not bring any useful knowledge, it makes sense to close them as off-topic. But the good news is that the question already has an answer that is correct, so hopefully your problem has been solved.