In Vagnuard’s groundbreaking research, they find that an advisor’s true value is from the more boring elements of financial planning. They list the top five quantifiable ways that advisors can save client’s money:

Behavioral coachingEncouraging clients to stick with their financial plan (even when the markets can feel scary) saved the clients in the study an average of 1.5% of their wealth.
Spending strategyChoosing which accounts to use for goals including retirement, inheritance, and other big milestones saves some clients up to 1.1%.

There is a limitation though. Only clients who had multiple types of accounts (e.g. Roth, Traditional, Brokerage, etc) saw the benefit.
Asset locationSaving to accounts that are appropriate to their goals can save clients up to 0.75%
RebalancingAdvisors managing assets choose the appropriate time to buy and sell investments to make sure they align with the clients’ goals. This can create up to 0.26% higher return compared with a portfolio that is not regularly rebalanced.
Cost-effective implementationAdvisors can help clients understand hidden fees and costs in a financial plan. Overall, this saves the average investor from the study 0.34%.