Pros and cons
The main benefit offered by a multi-asset fund is that you hand responsibility for how your money is invested and diversified to a fund manager, who you then rely on to make the right investment decisions.
By investing in one fund, which holds several different assets, you can effectively spread your risk. In theory, the performance of the strongest assets should offset the performance of the weakest, leading to steadier overall returns.
However, if one asset performs exceptionally well, you miss out on the returns that you would have enjoyed if you just invested in that particular asset. It's important to appreciate that, no matter how much you diversify, your investments can still fall in value and you may get back less than you invest.