I wouldn't worry about it too much. Does any organic traffic actually land at that site? Not really. Does it have posts by Satoshi, Hal, Vitalik & other crypto-luminaries of our time? No. Does it have 12 years worth of content & backlinks? No.
Here's a quick comparison of the site's traffic metrics according to Similarweb:
Bitcointalk Global Rank: #39,778 Worldwide
Altcoinstalks Global Rank: #540,599 Worldwide
Bitcointalk Monthly Visits: 1.5 million
Altcoinstalks Monthly Visits: 45.4 thousand
Bitcointalk Traffic Sources: 42.54% Search
Altcoinstalks Traffic Sources: 10.45% Search
I assume the campaigns there are paying peanuts compared to here. Also, its got to be a complete spamfest, which is why its not attracting organic traffic. If people want to make a few extra bucks by posting there, good for them. I don't think it will detract from Bitcointalk's status.
Just visited one of the mixers that was transferred from here to altcoinstalks and from what they used to pay their users back here, the 50 bucks pay cut is a brutal one. The thing is that the other forum's just not marketable enough for them to pay their users any higher than 30 bucks, and the sad thing about this is that since it's not that profitable, they literally have to play the pioneering game and Oregon trail settlement their shit out which is not that cool especially if you're doing it solely for volunteer work.
It's not like the other forum's bad either, did a couple visits in the heat of the mixer bans discussion and I see how similar these sites are to each other which is a good thing, cause it means people can really just go back and forth from here or there without much issue, but the sheer lack of enthusiasm around people, as well as the extreme profit-centric energy that the site gives out (they pay their users for being good boys with altcoins I think) is a stark contrast to the indie-vibes that we bring about in this forum, where people are still getting paid for sure, but it's not like that's the only thing that we're concerning ourselves with.
One thing is for sure to me after finding out about altcoinstalk and how they work there: bitcointalk will not die if the site loses all its signature campaigns and they switch out to altcoinstalk, but it for sure would be nice if it doesn't end up that way