> converting to a different currency, sending money, and converting it back

No need if you earn and spend it.

> You also get the volatility of bitcoin

Absolutely true in the short term, absolutely false in the long run. Bitcoin's volatility has statistically declined as its usage has increased.

> using it for a simple USD->USD money transfer is like using a jackhammer when you need a scalpel

Cannot argue there. The key is to stop using USD whenever possible.