Can someone in the field make a better widget than one who is not?

Usually yes, but not always.

There are rare instances where a trained/experienced professional will develop blind-spots and/or erect mental walls that don’t actually exist. While those in the field are far better at refining existing knowledge, those that lack that tend to be better at “thinking outside the box” simply because they never built a box to get into in the first place.

Usually the most creative ones are those with a little knowledge of the field their invention is in while having great experience in a somewhat related field. For instance, as a machinist, I’ve occasionally been stumped by something that one of the maintenance guys comes up with a simple-but-workable solution. He may not know an end mill from a face mill or the difference between G00 and G01 but he does know a few things about putting stuff in vices and moving heavy objects, so there is enough overlap in knowledge.

It should come as no surprise that most of the truly inventive people are multi-talented, able to use their knowledge of one field to break through the barriers that another field’s training/experience may build. Maybe a plumber has an idea for an artificial heart; after all, the heart is a pump. Or maybe a guy with a wood stove comes up with a way to split wood faster despite lacking a degree in engineering or physics.

Lateral thinkers are the true innovators.

Sometimes Yes. Sometimes no. The people in the field might identify the need and suggest solutions but they might not have any idea of the hidden but important characteristics required to make a truly successful, safe, cost-effective device. Depending upon the application the metals used must be strong, or brittle, or tough, or light, or ductile, or case hardened, or heat treated, or conductive, etc. Yet to the untrained eye the metal looks like, well… metal. The electronics, software, manufacturing processes all might have similar special requirements unknown and unseen by the user.
A collaboration is usually yields the results.

It’s a bit like going bird watching with experienced birders. I look at birds and can readily ID a Blue Jay or a Cardinal or duck. But I classify the vast majority as LBB, little brown bird. Meanwhile the birders are calling out “Oh look! A female Pine Siskin!”

The Wright Brothers built bicycles and wound up inventing the first reliable powered flight airplane.
There you go

In 1909 the War Department gave the Wright Brothers $30,000 (equivalent to nearly $1,000,000 in 2015 dollars) to support their work. That helped, too.

Wright Brothers were actually not the first flyers.
They were just ruthless business people who suppressed reporting of other earlier flights (e.g. Whitehead) and sued the heck out of others with aeronautical inventions prior to theirs (e.g. Curtis), and their estate made a then-secret deal with the Smithsonian to never note anything about prior flights in exchange for letting the Smithsonian have the Wright flyer on display.

The 1903 Wrights flights at Kitty Hawk were launched from a rail, landed downhill from the takeoff location, didn’t get very high, were out of control (esp could not be turned under control), and ‘landed’ with such force that after two very short ‘flights’ and one a little longer (the one erroneously claimed to be powered, controlled, ‘first flight’) that damaged the craft so it couldn’t fly again for several months.

On August 14, 1901 Gustav Whitehead of Fairfield, CT, flying farther and higher and for more time than the Wrights. Whitehead’s plane had two motors, one for the wheels that allowed his craft to takeoff and land on an open field. Whitehead’s craft also had warping wings that enabled controlled turns several years before the Wrights figured that one out.
The August 1901 Whitehead flight took off from level ground, was under control the whole time, landed without damage to the craft.
The Wrights are known to have visited the naive and generous Whitehead between 1901 and 1903 and Whitehead enthusiastically shared engine designs and some wing concepts with the Wrights.

I thought question was whether or not somebody not associated with a particular field could contribute innovation in that field. Bicycles to airplanes seems like an example of something like that.

But thanks for the predictable Fluther-style history revision. Always enlightening.

Indeed @josie your basic point is on, bicycle makers (machinists) did get a lot accomplished in a relatively unrelated field.
Whitehead made a meager living making engines of very advanced design for the day, but he also studied the designs of glider makers, especially Lilienthal, and his flyers had advanced design elements that weren’t incorporated into commercial aircraft for a couple decades and are still used today, e.g. ailerons.