No, term insurance is a great idea until you retire. If you get hit by a bus, it's the absolute cheapest way to ensure that your family and kidlets have enough money to keep the lights on for the next few years.
After you retire, though, you should have a decent slug of cash under your belt, and no more dependents (well, hopefully, unless your lazy-ass kids haven't gotten their act together and moved out). And if you have no dependents, you don't need life insurance: you can pass money on to your heirs without paying an insurance agency to do it.
You are correct, except it only works if you're a disciplined investor. If you have no heirs, it also means there's probably nobody to support you in your older age as well (talking about critical illness here). If you have heirs, some prefer paying out of their pocket while some prefer the insurance company to do it for them.
Some people choose to have the insurance company support them in times of need, others want to depend on their investments. Go with whichever strategy you like. When you're ill though, can you still make sound and rational investment choices? Will you be caught at a bad time like another 2008?
I'll give an example, since you seem to like your numbers.
ANB 30 Male Non-smoker
Coverage till 65
Death 500k
C.I 250k
Premiums $1,492.50/Yr
Same guy
Coverage till 100
Same coverage
Premiums $2,720.00/Yr
Difference in premiums = $1227.50/Yr
Assuming you are
very disciplined and know what you're doing, over the next 35 years this becomes $136,786 at 6%, and you lose the 500k Death coverage and 250k C.I coverage.
In the next 20 years (age 85) you are now investing your $136,786 along with the $2,720/Yr.
You're now sitting on $538,748, but from 65-85 there is zero coverage.
Let us have this scenario now, you pass on at 75.
From 65-75 you will be investing $136,786 along with the $2,720/Yr for 10 years, which works out to be $280,815.
Your family just received $219k less compared to continuing the term plan when that scenario happens.
If you pass on at 85, congrats, you've left behind $38.7k more than what you would have getting a term. Any age past 85 would definitely favour the disciplined investor.
Also last thing to add, I hope 6% ROI is achievable for the masses, if not the calculations will be way off even if you get just 5%. Way off in the term insurance till 100's favour, and they have to have the discipline to invest
every single dollar in difference.
One can argue that sitting on liquid cash is good because of the obvious liquidity reasons, but what would you need the liquidity for if you're well insured? Unless you plan to start your own company or give a lump sum to your heir.
Different people have different strategies. Not everyone is a disciplined investor. Not everyone can achieve 6% ROI. Not everybody will follow your strategy, or think yours is the best.
My few cents worth of thoughts.