It's partially a product of the widespread availability of LLMs. Criminal organizations that would previously have been limited by the language fluency, scale, or technical competence of the labor available to them can now use LLMs to supplement their operations. It's also helping them target new populations that you're more likely to be in alongside traditional victims like the elderly, the desperate, previous victims, etc. They're pretty slow to adopt new technologies, so scam usage is still ramping up.