The real problem with current keyboards is the physical arrangement of the keys. Staggered rows instead of columns make them less ergonomic, the oversized spacebar wastes much of the most valuable space on the keyboard. The thumb as one of the strongest fingers has almost nothing to do, with both thumbs mostly sharing a single key while typing text. While the weak pinky finger has to cover more keys than the others. These things are more significant than qwerty vs dvorak.
Need to type faster? Spend some time practising every day and you will gain more speed within weeks than from just switching layouts. Most people don't as speed often isn't actually that important. I myself am bottlenecked by my brain, not my typing speed. Need less hand movement? Placing symbols, arrow keys etc as secondary function onto the central keys with a programmable keyboard helps with that, changing to dvorak doesn't as much because on a modern keyboard you can reach all letters without hand movement either way.
"The thumb as one of the strongest fingers has almost nothing to do, with both thumbs mostly sharing a single key while typing text."
To be fair, that single key is used rather excessively compared to the rest.
That key makes up about 15% in English text, and it could be covered by 10% of fingers but instead it's 20%. Meanwhile every use of shift, return, backspace, ctrl etc is done with the weakest fingers and often include some hand stretching to reach those keys. Altough I haven't looked at actual keypress stats and how those are distributed across fingers. Might be interesting to look into.
On my keyboard I cover six keys with my two thumbs. It eliminates almost all hand movement and guess what, I feel a difference in my pinky fingers but not in the thumbs. I'm not saying every keyboard should be like this, but I think on a large scale you can probably improve wirst and hand health in the population by making a few small tweaks in how keys are arranged.
> Meanwhile every use of shift, return, backspace, ctrl etc is done with the weakest fingers and often include some hand stretching to reach those keys.
As previously stated, this is only an issue for non-practiced typers. With practice, it no longer feels like stretching. It just becomes muscle memory. It's like a novice golfer complaining that it hurts their hips when they rotate through the swing, or a tennis player complaining that trying to add spin with a wrist twist feels weird, or any millions of other example of "feels weird without practice". Hell, most people can't do the most basic of yoga poses without practice. Muscles need to be stretched and trained into doing what you want them to do. Once they are, all of the complaints go away and things feel normal.
Is QWERTY the most efficient, no. But as someone else commented, speed is not my issue. Thinking what needs to be typed is definitely my speed regulator. If I were to just do basic text dictation or re-typing while reading a direct source, my speeds increase dramatically.
I find that most typing complaints are from those that never had formal typing instruction and are self taught with games or similar. I was fortunate to have one full year of typing while in high school, and it is by far the most used class instruction I've ever had.