If you’ve opened the Trump Accounts app, the pitch for investing is hard to resist. Enter a $250-a-year contribution, and the app shows the user would have $19,000 by age 18 or a whopping $878,000 by age 55. Bump it up to the $5,000 annual max, and the numbers jump to $271,000 and $13 million, respectively. That eye-popping figure comes straight from the government’s own projection on TrumpAccount...