My small company employer has offered Fidelity Keogh plans for years and now SEP IRAs. We get full brokerage window access, including low cost Fidelity mutual f

My small company employer has offered Fidelity Keogh plans for years and now SEP IRAs. We get full brokerage window access, including low cost Fidelity mutual funds, commission-free low cost iShares ETFs, $7.95 commissions on all other stocks and ETFs, free Treasury auction and secondary market bond trades. I don't think it's costing the employer much of anything. What am I missing?