I've found the biographies from the channel 4 site
Charlie
Occupation: Furniture maker
Location: Edinburgh
After working as a computer-aided designer and dog walker, Charlie began an apprenticeship at the age of 30 to retrain to work in the world of woodwork full time. Charlie’s specialisms are furniture-making and carving. Since filming, Charlie has set up her own woodworking studio and lives in the Calder valley.
Misti
Occupation: Sculptor
Location: Ludlow
Misti worked for over 30 years as a high-end, interior designer working in mansions and stately homes. A few years ago, Misti decided to leave it all behind and now works out of her woodland workshop, sculpting from stone, wood. Misti says her strength in the competition will be her eye for design and her knowledge of wood and what it can do.
Radha
Occupation: Junior cabinet maker
Location: Watford
Since graduating from his product design course, Radha worked briefly as a junior cabinet maker for a furniture company. His love of woodworking comes from spending time in his uncle’s workshop as a child and learning about tools and working on small projects. Radha describes his style as traditional and fine and he enjoys using as many hand tools as possible. Since filming, Radha has set up a bespoke furniture making business.
Billy
Occupation: Builder & novice carpenter
Location: Lancashire
Billy completed a campervan conversion when he was 15, won a carpentry award at 16 and rebuilt a narrow boat by himself at 17. He has completed a two-year carpentry course as well as learning skills from YouTube, trial and error and Hayne’s manuals. He is currently working on a barn conversion and says he’s a quick worker and isn’t afraid to take risks.
The rest are here www.channel4.com/press/news/handmade-britains-best-woodworker-meet-woodworkers
Basically, all the true hobbyists have gone and we're left with people with experience. Except maybe Misti, although it explains why her pieces are all very sculptural.