Shad you're forgetting one thing: leather armor is better for sneaking than gambeson because it's made of HIDE.

It's a good thing I wasn't a soldier in ancient or medieval times because I'd go to battle dressed as the Michelin man.

Gambeson is probably not the best choice for those out in the field for five days in the pissing rain.
Carrying 20kg of cold water around is going to cramp anyone's style.

Hi! I'm a farmer from one of the historicly most flax intense areas, and can say without a doubt flax IS NOT easy to grow. It's a real pain in the ass to grow proper flax good enough to make linen and it require land and work similar to or larger than husbandery and tanning. The flax in itself will pretty much curse the soil for years to come due to its massive nutritional needs making it suitable at best for cattle to graze. Furthermore, you do NOT use cattle for work or milk until they die. Only really good working animals are kept, the rest are slaughterd as they are worth more dead than alive, usually when they are 1-3 years old. Sorry for being a little wordy and nerdy, but flax really is a boar to work with. :)

What if the leather armour was enchanted

Two things cows love more than cud:
1. Chick-fil-a
2. Shadiversity

But what about dragons

Will it protect you from them

The easiest ways to get Shad to notice your comment:

1. But what about dragons!?
2. Machicolatioooooooooooooooons!
3. Sword memes
4. Something about Overly Sarcastic Productions

As someone who has actually studied medieval clothing. You're wrong in terms of pricing when it comes to flax vs leather (and the true winner is wool).
Linen was fairly expensive, since both growing flax (in sufficient quantities) and working flax into linen is incredibly labour intensive. Sufficiently labour intensive that linen wasn't really available to the poorest classes. They couldn't afford clothing made from a single layer of linen, much less armor made from a dozen layers.
Instead wool and leather were the materials of choice. Why? Because all the labour force you required to raise an entire flock of sheep/cattle over the summer was a single teenage girl or young woman who you sent into the forests/hills/mountains, and then in the winter they were fed with byproducts from food crops and fallow fields. Very economicly advantageous. While you're raising a sheep you will get several seasons worth of wool and finally meat. With cattle you'll get meat (frequently quite expensive meat compared to a pig or hen) and cattlehides.
Flax on the other hand. You'll have to devote fields of prime farming land, which will have to be plowed and the only stuff you get is flax seeds and flax. You might have to devote enough labour and acrage to growing that flax that you could have fed an entire family! Turning wool and hides into cloth and leather is (compared to flax) not very intensive either.

It was work and land intensive enough that Greece (which made sails and armor from flax, whose entire way of life was dependent on linen) pretty much didn't grow any of it themselves, but instead imported foreign linen.

It's not a coincidence that the only areas where linen was the primary clothing material was egypt which had great and deep fertile soil around the nile but absolute crap grazing lands (which made it expensive to raise cattle and sheep). If you have hills and forests you'll wear leather and wool instead. Even if you (like in ireland) have to keep a few lads guarding the herds to keep your neighbouring cattleraiders off your backs.

Uh, you wouldn't raise a cow just for the leather, leather would rather be a convenient by-product of owning cows.

Buff leather is not very stiff despite its thickness. It retains an incredible amount of flexibility at high thicknesses. Very few people today tan leather to the same properties as used historically (largely because we don't need it to perform the same tasks).  Medieval cuir boulli likewise bares little resemblance in performance and properties to modernly available leather.. Modern tests on modern vegetable tanned leather have almost nothing to do with what would likely have happened with historical cuiries and cuir bouilli.

"Stuffs Pillow in Shirt"
I AM READY FOR BATTLE!

Gambesons are also good protection against weather, like rain, wind, cold. They would only be a problem in the heat of summer, but then pretty much any type of armor would be.

What a lot of people tend to forget, is that leather armor is an RPG phenomena to separate character classes and creating a set of armor tiers. It disregards the fact that, as you mentioned, a gambeson can get very protective without adding much weight of reducing flexibility. And if they needed more protection, that's what mail or a birgandine is for. You would put that over the gambeson, and congrats, you have more protection.

My family's surname means linen maker for a noble so that means that they could had made padded armor which I think is quite cool.

I don't disagree with the factual statement that gamboised armor is historical in a way that leather (in Europe) was not.  However, I think you somewhat oversell how "cheap" a gambeson was.  Pre-industrial cloth manufacturing was hugely labor intensive.  Up until the 18th century the most expensive item in a common persons house was generally the bed because of the expense of even basic mattress/coverings.  This is directly linked to how expensive cloth was.

In my very homebrewed RPG I have heavily featured Gembeson.  And pretty much everything in your "Fantasy Re-armed" series.  Giants with slings are sort of an ultimate weapon

Light Armor means light on your feet smart

I'd love to see a video about Egyptian weapons and armor. This is cool stuff, thanks!

Leather is stronger against friction than fabric since it is am more homogenous structure. This means it is usefull as biker gear and tough working outfits. This may have lead to the idea that leather could be a usefull armor while the stress for armor in combat would be totally different.