Some merit badges involve strenuous physical challenges, such as hiking (multiple long-distance hikes including a 50-miler). The canoeing MB requires learning how to get back on an overturned canoe while in deep water, which is bloody hard.
They still have badges for shooting and archery, too.
There are also some badges that were unexpected - plumbing, fixing farm equipment, computer game design.
I remember getting my computer badge- in the late 90s, iirc. I had to write up a document in a word processor, create a simple spreadsheet, and one or two other things I'm probably forgetting. Even then it felt a bit basic and behind the times, but I was happy to get an easy badge!
Ah yes, the canoeing merit badge. Accomplished by yours truly and one other scout because I found an underwater stump in the Sewanee river and told him about it. LOL.
I had a habit of collecting unusual merit badges that few had seen before: Animal Science (hey, it's got a cow on the badge, and besides I had cows), Atomic Energy, etc. I got my Entomology merit badge at the National Scout Jamboree from a team of highly motivated active duty Soldiers who had the job of eradicating potential disease vectors from areas where our troops would live and work, even during wartime. They were so happy I stopped at their little booth — I'm guessing the majority of Soldiers treated them like the bulk fuel folks (or other unsung jobs) rather than the people who keep you from contracting some horrific tropical disease.
The head of the team was a full bird colonel with a PhD from IIRC Cornell who revelled in the fact that .mil is exempt from EPA regs. They got to use the heavy artillery of insect control means. He flatly stated, with no small amount of pride, that not a single Scout at the National Jamboree that year would get Lyme unless they went into the (untreated) woods. My father was a staff physician for the Jamboree, and as best as he could tell the colonel was right — now, they did have Lyme infections from kids going decidedly "off piste", this being Fort AP Hill, VA, in the summer.
The lifesaving merit badge was the hardest for me. Lots of swimming and you have to lift a weight out of the deep end of the pool. Didn't help the camp that we did it at was at a high elevation in Colorado.
Unfortunately I didn't stick with it long enough to go on any of the famous backpacking trips. That being said, Boy Scouts was a valuable experience that offered some cool experiences no other organization offers around that age.
Hiking requires one 5-mile hike three 10-mile hikes, one 15-mile hike and one 20-mile hike.
None can be overnight.
The Backpacking MB requires a 30 mile trip over at least 3 days or nights (3 overnight stops).
None require a 50 mile hike, though there is a “50 mile” award that requires at least 50 miles over 5 days with no motor vehicles. Some troops (units) make a 50 mile trip compulsory in order to attend the High Adventure base trip (e.g. Philmont.)
They still have badges for shooting and archery, too.
There are also some badges that were unexpected - plumbing, fixing farm equipment, computer game design.