I've said no, as I have never had adverts anyway, on a phone.
If it had to be one or the other, I would pay a subscription, depending how much. Adverts used to make mobile devices unusable here.
The advantage is, no spam, as few people would keep trying a site where they had to pay to spam, and were immediately banned.
The disadvantage, I suspect most long-term posters found the site by mistake- and may not have joined, if there was an immediate payment needed.
It would also mean, if people were suspended, they would need to know how long for, so they aren't paying for a site, they can never rejoin.