Imagine you are looking at a coverage of $250, 000 for Death, TPD and Early Stage CI coverage. Anyone of those occurring and you would like a payout of $250, 000. However a high sum assured like that is going to be expensive. Thus, you can work around a few permutations, for example:
A sum assured of $50, 000 with 5 times multiplier ($250, 000) and a sum assured of $125, 000 with 2 times multiplier. Both provides $250, 000 of coverage until age 70 (most insurers at age 70, with certain insurers until age 86 or even life).
That being said, after the age of 70 (or when the multiplier ends), the payout will be basic sum assured ($50, 000 or $125, 000 in this case) and yield it garnered throughout the years.
So why would someone choose a lower Sum Assured and a higher Multiplier benefit? The main difference is that the one with $50, 000 sum assured is going to be cheaper than the sum assured of $125, 000, as the cash value is going to be higher for the $125, 000 one and the premium calculation is based on sum assured.