Eh. It's irritating, but it's also understandable why they do it. It's easier to just put things in one place, and you go where your audience is.
I don't InstaFaceTube, but the draw is having your content put in front of people without them having to "go find it." Gun people browsing TwitchBook completely unaware that Beretta is importing these things will have it put in front of them, albeit subject to the whims of The Algorithm. And as The Algorithm gets smarter, the tiny subset that will plunk down $3k for a European revolver will have it front and center. Meanwhile the others will have whatever Beretta fits their demographic's optimal price point show up at the same place on their screen
Web fora like PF that are focused on one specific type of content have mostly evaporated or gotten absorbed into a network of fora that are increasingly owned by like one Canadian company. Anything that isn't on the TokGrams is eventually going to be on whatever social media type service SMC is putting together now that they own hkpro, and 1911forum, etc. There's a shrinking number of places for anyone to hear about it outside the Walled Tech Gardens. So might as well announce it there in the first place.