What's wrong with QWERTY?
Well, it was designed for the mechanical typewriter of the late 19th century. The considerations Mr. Sholes had to make are simply no longer necessary or valid.
Neighbouring levers of the typewriter were prone to jam, that's why Sholes moved frequent character pairs away from each other. We still have the obsolate horizontal staggering on common keyboards for the same reason (because of the levers), but when did you see a lever last time in a keyboard? There are none. There were never any levers in computer keyboards I guess.
So the main idea behind the arrangement of characters lost its cause decades ago. The very problem QWERTY was meant to solve doesn't exist anymore.
On the other hand we have problems and development goals which would need to be addressed: speed, finger travel, ergonomy etc.
How bad is QWERTY?
Of course it depends on your language and the national variant you use. I made a simulation with the QWERTZ layout, a large Hungarian corpus and my Golem evolution model, and the performance of QWERTY was good for the top 1.82%. Wait, what?! QWERTY is in the top 2%? That's not bad at all. It beats 98.2% of all the layouts.
Right. But imagine how many potential layouts there are. I optimized for 38 chars on the base layer. The number of possible layouts is 38 factorial, which is 5,23*10^44. 1.82% of this is 5.13*10^42. That's how many layouts are better than QWERTZ.
Let me help you imagine that:
5 130 000 000 000 000 000 000 000 000 000 000 000 000 000
So QWERTY beats 98% of RANDOM logical layouts. I'm sure we can find a much better one if we put some effort in it and not just try random ones.
The aim of making the Golem evolution model was exactly this. To find an optimal logical layout for myself typing mainly in Hungarian.
During typing the corpus used for the calculation above, your fingers would travel 314 kms. With some optimalization this number is down to 197 km. Similarly, with QWERTZ the number of row changes is 22%. Optimized: 10%. Base row keypresses: 33% vs 53%. Home row jumps: 6.6% vs 1.3%.
Wether you choose one of the popular alternatives like Dvorak, Colmak, Workman etc. or find your own unique layout, you better do it as soon as possible.