Earlier quoted context omitted.
The calculation is at https://double.finance/pricing They are assuming an additional $2000 contributed per month and a 7% return.
Handy calculator. Comparing to VTSAX (.04% expense ratio), they show a 1% difference. Not nothing, but hard to justify switching when you consider the downside risk of this company going out of business or selling in the next 30 years. I think this is going to be a hard product to sell when your target market is exactly the sort of people who are well-informed enough to just buy vanguard mutual funds for a nearly ide…
The risk of them going out of business, fraud, changing strategy, being bought, vanguard fees going down even more, etc - it's not even close to being a sensible decision to move for what amounts to significantly less than 1% at the end.