I've had the same three investment accounts for 11 years and I want to share why I've never once thought about switching.

Fidelity holds my Roth IRA and taxable brokerage. Vanguard holds my HSA (rolled from my employer's plan). My 401k is through my employer (Fidelity again).

Everything is invested in variations of the same two or three funds: total US market, total international market, and a small bond allocation. The expense ratios are under 0.04% across all accounts. Dividends auto-reinvest. Contributions auto-invest monthly.

I've never had a reason to switch because there's nothing to improve. The funds are the cheapest available. The platforms are reliable. The automation handles everything.

The personal finance media cycle suggests you should be constantly evaluating and optimizing. In practice, setting up a simple, cheap, automated portfolio and leaving it alone for decades is the strategy that beats almost everything else. Inaction, when the setup is right, is the optimal action.