We found 6 Reddit comments about The Big Scrum: How Teddy Roosevelt Saved Football. Here are the top ones, ranked by their Reddit score.
You're probably right that those sports won't be around for long, now that we know about the injuries caused by them. However, if you think that's the end of those sports, you're probably off.
I want to use football as the example here. Before the 1900s, Football was a lot like rugby (which Americans see now as "football, but super violent because they don't use pads"). Obviously, safety gear was less effective and less common, but also the sport had a history then of violence based on common tactics used by teams at the time (turns out, large masses of people bashing into each other like a mosh pit at a concert isn't healthy in any context). In 1905, the body count of the sport hit an all-time high of 19 deaths that year from playing football. And as this sport was played by young men in college, some were worried about the risks to the health of their children and loved ones who played the game. President Theodore Roosevelt actually threatened to shut down football as an organized sport if changes couldn't be made to make the game safer (note that while Roosevelt definitely called for changes to be made, historians dispute that he threatened to close the whole thing down. But I digress). Several fundamental changes to the game were made at that time, including banning "mass formation plays", banning interlocked arms and legs as a way to stop oncoming players, and introducing the forward pass as a legal play. The result was a game that was, in many ways, different from football at the time, but was much safer as it widened the field of play and prevented the massive concentrations of bodies that led to the worst injuries in the game.
Now, let's get back to the point here. What I'm saying is that yes, if the sports you mention are going to continue, they'll have to change drastically in common-sense ways to prevent injuries for the players. But at the same time, that doesn't have to mean that the sport is "doomed". We've made changes to the games in the past, and there's no reason we couldn't do it again and still call the game football (or boxing, or MMA).
EDIT: There's actually a published work that talks about those football reforms, for those who are interested.
Teddy was an important figure because he was under a lot of pressure from institutional heads to reform the game. There was a book I read a few years ago called The Big Scrum the spoke about his involvement in this in length. Teddy may have helped bring about the talks that lead to the creation of the forward pass, but it was Harvard in the end that sealed the deal (pretty much all due to the fact that their brand new stadium was made of reinforced concrete).
There's also a book on it, if you're a reader:
The Big Scrum: How Teddy Roosevelt Saved Football
The Big Scrum: How Teddy Roosevelt Saved Football is a good, easy read.
The Big Scrum is my go to recommendation for a history style text. You have a players flair so I am not sure The Essential Smart Footbal will be meaningful for you to read, but its a great book nonetheless.
there was also an interesting book about it, the big scrum. read it recently. it jumps around a lot, but tells the whole story.