AOA
iShares Core 80/20 Aggressive Allocation ETF
stock NYSE ETF

At 20% AOA is the max I ever want to be in bonds. At 15% I think FFNOX is at a perfect amount to smooth out the volatility while not being a real drag on gains. I'm almost 48 though, so my timeline is different than yours.

The most simple set it and forget it fund is AOA.
80% in stocks (roughly 60% from the US & 40% international) and 20% in bonds (for that stability you may want)

I consolidated my Roth holdings into FFNOX (Fidelity Multi Asset Index Fund) and so far I'm happy. It's a very Bogle kind of fund. I believe Vanguard has similar funds (lifestrategy or something like that?). AOA or the other iShares allocation funds are also good if you want an ETF. My brokerage is straight AOA. I like the simplicity, what can I say?

Here to support. The LifeStrategy Funds are flat out underrated.
And at least in the US there are tax-efficient equivalents from BlackRock also! Like iShares 80/20 Core (AOA).

Vanguards forecasts are ridiculously bad, but every other forecaster is just as bad. They don't know the future any better than anyone else. I personally hold zero weight to any forecast of the market. What will be will be. Embrace the unknown and build your finances to work for you regardless of what the market does.
Me, I'm 80% global equites and 20% bonds. Since I'm lazy and also want to avoid any behavioral/emotional trading, I pay the convenience fee and buy it in a single ETF: AOA

At 55, capital preservation should be your priority, VOO and VXUS are too risky now. Consider putting your funds into AOA for the next 5–6 years, then rotating into AOR. This approach offers diversification, manages risk, and avoids the need for rebalancing.