This is my point of view from a shameless newb with some decent riding skill.
I got back into biking this year after likeeeee a 14 year hiatus from my BMX champ glory days. I never, ever had a mountain bike, and I used to ride trails a lot as a kid....one a 20 inch bmx bike.
So I got my bike a couple months ago, and obviously started with flats. My endurance is not the best, so I was struggling to ride up climbs, and it was discouraging. I put &^&^ty flat pedals on my over $2k bike, and didnt really have good riding shoes.
After some thought, I decided to give clipless a try. It was kind of scary lol and like the idiot that I am sometimes, my first day riding clipless just happened to fall on a day when I took my first road trip to Dupont with some pretty experienced riders. I actually did pretty decent that day, but I did fall probably 2-3 times pretty hard going up climbs when I lost traction going over a log or something.
The worst fall I had that day was actually in a parking lot, in front of everyone, and it hurt lol.

Dont forget to unclip!
Fast forward a couple months, I am becoming a better ride, and the clips definitely help me a lot with climbs and even confidence going down hill. However, when I ride trails that are unknown to me, and am riding with someone that is a very good rider, I still have troubles through some technical parts while trying to keep up. Last time I rode clipless at WWC, I fell going up the carpet climb because my tire slipped, lost traction, and I went down. No biggie. Next trail we were riding pretty hard, and was going up a short steep climb with a log, and almost got over it, but I lost momentum again, and fell to the side, and slammed my ribs into a small tree.
.....2.5 weeks later, I can finally kind of go to sleep laying on that side of my body and the bruising is almost gone!
After that day, I ordered some good flats and some better riding shoes for flats. I tested those out the other day, and wow! I always thought a flat pedal was a flat pedal was a flat pedal, but good pedals and shoes do make a difference.
My plan now is to develop some better technical skills utilizing the flats. When I go to ride trails I know very well, I will put the clips back on and once I get more confident in my skill, I will probably put the clips back on 100%.
If you are afraid of falling, dont go clipless. It'll happen and itll hurt, unless you are a natural born freak of nature rider. However, dont let it get you down, it is all part of progression, and you will notice that you can ride a bit more with clips because you truly get so much more energy every cycle of the cranks.
Good luck!