Are the forum links still working?

Hello everyone, this is my first post on the forum. I would like to know your opinion about backlinks from the forums. Yesterday one of my clients said that he would no longer buy links from the forums because it no longer work. He says that 3 guest posts a month is better than 50 forum links. What do you think about this? Is it even possible to compare these ways of getting backlinks? I'm interested to hear the opinion of each of you. I have been posting links on the forums for 4 years now...

Are the forum links still working? WordPress ...