Depends on where you tour ...
If you are touring in a dry region -
The American West, Australia, Central Asia, etc.
Then a wet sock is far, far superior to insulated bottles.
Plus, the bottle holds more water and it's way cheaper.
The method was shown to me by a young woman back in September of 1987.
She was just finishing a tour in Oregon and I was just starting.
Some of the best advice I have ever received.
Just a plain ole plastic water bottle.
I use a crew sock - I cut off the foot portion. The key is keeping the sock wet.
I carefully squirt out water before the sock dries out completely.
It does use up some water - you need to keep the sock wet.
It's the same principle as evaporative coolers that keep office buildings cool.
Water evaporating from a surface cools that surface.
With a breeze from riding, the cooling is faster.
In places like Nevada, I have had 50F water on a 100F day.
As for leaking - don't recall any issue with newer bottles.
And if a little water leaks, if just keeps the sock wet anyhoo..
Now, once a plastic bottle has been out in the sun for a few years - then no.
Surely you can spring for a few basic water bottles every few years.
BTW - Back in the olden days, people driving out West
always had a canvas water bag strapped to the front grill.