Functional regulation in the 21st century: What’s reasonable for investor protection and for agents selling variable annuities?

If complaints about an agent’s sale of “ABC” mutual fund are handled by the state securities commissioner… Why should complaints about the same agent’s sale of a variable annuity invested in “ABC” mutual fund be handled exclusively by the state insurance commissioner? Are state laws enacted 35 years ago still relevant today when most agents who sell variable annuities are also licensed to sell mutual funds?