How much a couple making $160k/yr needs to be saving

How much a couple making $160k/yr needs to be saving every single month. Before you say that nobody makes this amount of money, about 20% of households in America make $160,000. After paying taxes, this is probably closer to $120,000. So $10,000 a month. Now this couple should be saving 20%, which means they need to be saving $2,000 a month. What they'll do with that $2,000 a month is they'll each fund their own Roth IRA, which would cost $625 a month if they wanted to max it out. Then that last $750 should go into their 401k, especially if they get employer matches. Now inside these accounts they should just be investing in low cost index funds. Here's a few examples like VOO, VTI, and FXAIX. Because if they just did this for 35 years, they would have $6.1 million available to them tax free in their Roth IRA. Which in today's value is still $2.8 million. Plus they'd have $3.7 million available to them in their 401k and that's not even counting any sort of employer match, which in today's value is $1.7 million, for a grand total of $4.5 million. And that would mean that they can live off $180,000 during their retirement.