3 ideas
Wealth should be measured by whether it can reliably fund the life you want for as long as you need it, not by how large the pot is or how much it beats a benchmark. Once you define 'enough' and cash-flow model your future spending, decisions about risk, saving, and gifting follow from the gap between what you need and what you have, not from chasing returns.
Most of the long-term variation in portfolio outcomes comes from the mix of asset classes held and the total costs paid, not from picking skilled fund managers or timing markets. Because active managers as a group cannot beat the market after fees, a low-cost, broadly diversified, passively implemented portfolio that is rebalanced periodically is the rational default for private investors.
Where you hold an investment matters as much as what you hold. Tax-advantaged wrappers such as pensions (tax relief on the way in, tax-free growth, restricted access) and ISAs (no relief in, tax-free growth and withdrawals, full access) should be filled in an order set by your marginal tax rate now versus later, and by when you will need the money. Assets likely to generate the most taxable return should be placed in the most sheltered wrapper.