I actually recently had a battery failure after about 9000 miles on my EUC and it just disabled the failed battery and told me "please repair" while keeping me from faceplanting with the other battery. All my crashes have been either skill issues on my end or cars existing, fuck cars.
They're always getting safer and more powerful, and those two do actually go together in self balancing vehicles. That's why the Onewheel is so unsafe, because it doesn't have the power or redundancy to have any safety margin like EUCs do.
They deliberately built the Onewheel without any speaker or even beeper to warn the rider because they thought it wouldn't be "cool." An Inmotion EUC pushed to its limit will tell you "overload, please get off" and gently slow you to a stop, a Onewheel pushed to its limit will just fuckin drop you.