In the banner above you see the formerly ubiquitous J-38 straight key; the Vibroplex Blue Racer (bug); the Bencher BY-2 Iambic Paddle and the modern generic PS/2 keyboard.
Generally speaking the straight key is good for 0 - 20 WPM, and both the bug and the paddles are good up to around 50 WPM. Obviously there is some overlap, and, in the hands of competent operators, the ranges can be extended somewhat. Even so, fatigue is always a problem over prolonged periods of time.
In the last 170 odd years (since 1837) we have progressed from the earliest straight key to the computer keyboard. By doing so, we have increased our keying speeds from almost nothing to a hundred WPM, or even more. Some hams still refuse to use anything but straight keys, saying that's the "True Ham Way." Others are comfortable with bugs and paddles, but turn their noses up at keyboards. We, however, are going to embrace these new-fangled modern keyboards.
To increase speed even more, do switch from the QWERTY keyboard to the DVORAK keyboard. Just about all computer operating systems are now capable of easily doing this.
If you're already a touch typist, it may take a bit of effort to make the switch, but it's well worth it. After a few months of practice, you'll easily double your current typing speed.
And in no time you'll be ready to apply for a position as a secretary! hi!
But if you're just learning touch typing, get a typing course and learn on the DVORAK keyboard. I learned on the Mavis Beacon Teaches Typing program, which, last time I checked, was on version 20. Another good one is Typing Lessons for Dvorak. And there are plenty of other free open software typing tutors available. Google is your friend.
It's up to you whether or not you choose to limit yourself, but you have everything to gain and nothing to lose.
So abandon all those primitive keys and move into the twenty-first century! You'll never look back.
Having said all that, I must admit that I on occasion dust off my J-38 and work some of the code newbies. It's agonizing, almost painful, to listen to such slow code, almost like having someone spell out words to you to keep small children from understanding. But it's worth it to give a newcomer some help !