If obligatory, then it starts killing people. Consider football and concussions.
And then there's marketing. A certain amount of risk is accepted in sports, and is part of what makes it attractive to fans and sponsors. But when someone actually dies at an event, it overshadows everything else that happens. If that becomes a regular occurrence, fans and sponsors who pay for the coverage will begin to lose interest.
Part of the reason for rules in sports is to make a sport interesting for the fans, e.g., by preventing each match from being decided by a single factor that is predictable ahead of time. Financial sports already have financial rules. Pharmacological sports need pharmacological rules.
> chances are that it was unthinkable for a player to even be a contender for the elite level without doping.
Which is really the case for most sports today.
Other than security key, it's only phone number or adding account to the phone.
I'm sorry I didn't mention that in my post, I wasn't trying to lie, I just can't obtain physical key and I don't think I have to have physical key to read my emails.
Besides, you don't need an actual physical key for U2F.