That is honestly a decent analogy. So, on what rides is it ok if something goes wrong and a young family member is killed? Rust says, it is never ok so we won’t let you do it.
To use your analogy though, the issue is the driver feeling quite confident in their skills and rating the risk as low. Then a tire blows on a corner. Or somebody else runs a red light. Or, there is just that one day when an otherwise good driver makes a mistake. History tells us, the risk is higher than the overconfident “good” drivers think it is.
In particular, history shows that 70% of the real world injuries and fatalities come from passengers without seat belts. So, instead of each driver deciding if it is safe, we as a society decide that seat belt use is mandatory because it will prevent those 70% of injuries and fatalities ( without worrying about which individual drivers are responsible )
Rust is the seat belt law that demonstrably saves lives regardless of how safe each individual driver thinks they are. It is a hard transition with many critics but the generation that grows up with seat belts will never go back. Eventually, we will all realize just how crazy it was that they were not always used.
While I understand the sentiment, we have to understand that Open Source developers work on projects that motivate them.
So, we can have a single example of each of these but they do necessarily get any more devs. In fact, if you take economic theory ( competition for example ), it is likely they attract less attention individually than they do competing as part of an ecosystem.
It would certainly help on the user acceptance and commercial software side where choice is an impediment. But, if we are just talking resources, limiting the number of projects only works if you pay people to work on them.
Why was each of these projects started ( eg. window managers )? The answer is simple. It is because the founding developer did not like any of the existing options.