If you think the S&P will hold up until the day you retire, sure. In that case, I wouldn't use a TDF (because you have no target date); I'd move to a balanced

If you think the S&P will hold up until the day you retire, sure. In that case, I wouldn't use a TDF (because you have no target date); I'd move to a balanced fund such as Vanguard LifeStrategy. But a pure equity portfolio is considered very aggressive and risky for someone close to retirement. What if another 2008 happens? Bonds reduce volatility. Look at the mid-March 2020 drop. At the lowest, the S&P was -32% YTD. BND's lowest point was -4% and was positive 2 weeks later. S&P didn't pass zero until August, more than 5 months later. Bonds also allow you to lock in your gains. Being less volatile, the bond portion is much safer than stocks. Your main enemy there is inflation, which is why many TDFs supplement with US TIPS. I understand if you want to be aggressive. That's fine, and you don't have to use a TDF. I know J. L. Collins (who's retired) caps his bond allocation to 20%. But I don't think strategy is for everyone.