No, this is a myth that doesn't become more true just because many people perpetuate it without question.
QWERTY was designed to be as fast as possible for the first data entry jobs at the first companies that adopted typewriters and went through a couple iterations based on feedback of these first customers.
Is QWERTY optimal? No. But it's good enough that learning an alternative layout like Dvorak for months may cost you more of your lifetime than you'll ever get back by typing minimally faster(not to mention such a switch would be more costly with every single keyboard shortcut you've memorised so far).
Either way if you are waiting for a better alternative to become the standard so you don't need to carry your own keyboard you're going to need a lot of patience.
Hasn't that origin story been debunked?
e.g. https://www.smithsonianmag.com/arts-culture/fact-of-fiction-...
I don't want to know what my muscle memory would do if it got used to a Dvorak keyboard.
While not designed for best human use, it's not completely terrible.
Azerty vs Qwerty verus Qwertz is a different issue entirely.
I'm a Pom (British/Australian) living in Germany, so most keyboards in shared locations are unusable for me. Using other people's computers is a massive pain as my carefully-learned muscle memory is now actively stopping me from pushing the right keys.
I keep looking at Dvorak or a chord input device, but I know that if I get used to that then I'll have to carry one around with me always so that I can plug it in to whatever computer I'm using at that point. This doesn't seem practical.
I'd love another input option. One that was actually designed for humans to communicate fast with.