... There is really no point in deliberately holding on to them, you'll lose the freshness that makes them attractive.
Some people like the taste of aged wines. White wines will go darker in colour and the taste will change, maybe seeming duller.
There are exceptions and they will be the more expensive wines but the basic rule on white wines and inexpensive wines is DYA - Drink Youngest Available
True, the vast majority of all wines, red and white, are meant to be drunk early. Studies show that something like 95% of all bottles of wine sold in Australia are drunk within 48 hours of purchase. Wine makers would be crazy to ignore a statistic like that.
That said, many white wines do keep very well and can be enjoyed early or after several years in the bottle. Again it is true that many people enjoy the fruity crispness of a young reisling over its aged big brother, and an un-oaked chardonnay or marsanne is pointless to keep.
But I have never met a (dry) semillon I didn't like better after 10 years in the bottle, and the glorious golden colour of an aged marsanne or a 'properly made' chardonnay (it must be oaked for aging to do any good but I think a lot of chardonnay has got too much darn wood - if I want to chew on a chair leg, I will for crying out loud. But I can't drink those over oaked things young either) can be the harbinger of a beautiful friendship.
A dry reisling is admittedly a problem child though. It has this 'trough' it goes into and hides for a few years, but when it comes out it is terrific. The trick is to catch it before it goes to sleep, of after it wakes up.
An aged reisling is really not for a coca-cola palatte though.