Frankly speaking, you don't need a medical insurance beyond 80's.
The insurance premium is too extra ordinary high until not worthwhile to have one.
With 5 figure premium beyond 80's yo, not many people can afford it.
The one can afford 5 figure premium, then one is already rich enough, can self insured already.

No such thing you buy medical insurance at young time, then the premium will stay cheap when you are old time.

Medical insurance premium goes up together with ages.

Let the kids buy their own when they are financially independent.

Your family may not be burden with treatment cost.
But your family may be burden with ten of thousand premium needs to be paid every year.
Medical premium at old ages is not 1k or a few K pa.

Please be reminded that medical insurance is not covering everything, Outpatient cost, post treatment, nursing, medicine cost etc may not be covered by insurance. So there is still needs personal saving to pay for that.

Wait until when you old time, and every year pay such a medical fee up to 5 figure each year, then you will know or start realise the issues of paying medical at old ages, that I am talking about. 

After such an age, even one has critical illness like cancer etc, doctor may also advise not to under knife, as your body may not able to coup with surgery and chemo treatment as well.

That's why medical insurance cover until 70-80s is sufficient.
If cover until 100, means potential make medical premium become even more expensive and unaffordable to many middle class.

Remember insurance mechanism is like a pool of fund, when the pool of fund needs to be used those beyond 80s, means potential higher premium

Don't think there is investment linked that being structured to be self sustained until 99, I could be wrong.
Also, the longer the ILP is designed to self-sustained, the higher the premium could be.

Also, investment linked is just investing in unit trust, and those unit trust may not perform as good to be self-sustained until an ages as projected.
That's why you hear some investment linked send letter to policy owner to increase their annual premium, especially with recent financial market lackluster performance and turmoil.

Some investment linked unit trust may as well result in a loss instead of gain, even putting FD can beat those unit trust.

Basically, there is no guarantee the investment linked will make enough to cover or self-sustained, it may or may not.

Basically, there is no free lunch in insurance coverage, you can't "beat" insurance, and never think of trying to "beat" them.

Buy it if you needs it and when can afford it, should be the mindset.

standalone medical card are never meant for long term coverage since it doesn't allow you to add-on any other riders.

However if it fits your bill, go ahead.

Your understanding on ILP needed to be beefed up.
You paid more ILP compared to standalone, because you are paying extra premium in the early year, that being saved and invested in unit trust, which used to compensate or pay the increase COI of medical coverage later on, it never deter the increase of COI.
Please be minded the investment part also can lose money instead gaining, so you also took the risk of investment in ILP.

All still comes from your own money, it never lock in the medical COI due to aging and inflation in medical cost.

In a correct insurance pov, you don't or can't or look for premium saving. Insurance is drafted based on actuaries maths, it is computed based on pool of risk.
Please don't have a mindset try to save on insurance premium by buying early, late or whatever strategy, it doesn't work that way. Insurance is a consumable financial product, you need it, you buy it.

When old, everyone will need to pay more in medical coverage, this is how insurance works, and how insurance company can be profitable.

Life insurance only needed if your have financial dependents, if you are not married and no financial dependents, then life insurance is not urgently important, except CI/TPD.

Insurance is all about financial management and personal needs, there is no single or universal rules how and which insurance needed.
Fix rules or fixed % amount must be insurance, it just means insurance company and agent can securely make fixed % profit from your wages. It is about marketing only, which doesn't address the personal needs for insurance which  is different for everyone based on different individual financial position.