Well Singaporeans actually have one of the worst eye sights in the world, that is well documented in medical studies.
In general peoples' myopia don't get better, in fact they only get worse and worse. You probably would have found out if you have myopia that you have to get new specs made every couple of years or so. If your eyesight is already worse than 6/60 (just able to see the big E in the snellen eye chart) at your twenties, you can imagine how terrible it will be in your 40s and 50s.
Furthermore one tends to get longsighted as you get older as your eye muscles are unable to focus on near objects. Imagine if you get very short-sighted and long sighted at the same time. You'd need reading glasses as well as your normal seeing glasses. It will be fun seeing you fumble for your reading glasses to read checklists and then switch back to your usual glasses as you go back to looking outside.
LASIK, while wonderful in correcting your vision to perfect, doesn't change your predisposition to become myopic as you age. So if you get your LASIK done at 20 to obtain perfect vision, you might become myopic again at 30 and need another correction. There is only so many times you can burn out your corneas. Not to mention LASIK brings in some special side effects like dry eyes and halos/ghosting what not.
So yes, the standards you see from your class I medical are the minimum standards to fly. The moment you are unable to meet those standards, poof goes your medical and your career as a pilot. The standards for SQ and Scoot seems far stricter, but they have your eyesight in mind as a 50 year old captain and not a 20 year old wannabe. I don't think there are any captains flying that cannot meet the class I medical requirement. It will be terrible for you if you fail your medical at 50 and have no other skills than flying as a trade.
If you are rich, you can always self fund your private training and apply to scoot and other airlines from there. You take the risk upon yourself, the airline wouldn't care so much if you lose your license as you will be just a disposable hire.