ELSS investment which would be countable under 80C deductions is capped at 1.5L per year (though you can invest more than that amount in one/multiple ELSS schemes, the amount available for 80C will remain at 1.5L as per the current IT laws). On top of this, most salaried workers have PF, insurance etc., limiting ELSS investments to much lower value. If the investment principal is small, return difference isn't that important.