This is massively overstated. The major costs of being a spammer are creating new accounts and staying off blacklists. Carrying on conversations or creating content are marginal costs, at best.

LLMs are no more valuable to a large spam operation than they are to any other business. This is like a 5%-10% profit increase, not 50%-100%. The key to that game is finding suckers. Language models help, but only so much.