The whataboutisms are simply to determine if there is a point to...

The whataboutisms are simply to determine if there is a point to weighing the safety aspect when comparison is made to existing volatile substances used en-masse. There is, but it’s marginal. As for alternatives being found and used that could be safer. Found, developed, yes, used? Unlikely. The economies of scale and tooling/infrastructure put in place to allow lithium to replace lead cell in the first place took many many decades. A contender is unlikely to surface due to the substantial expense of developing the ability to manufacture at scale. It’s not a hill many major companies are willing to die on. They will simply mitigate the risk over time of lithium cell technology. It would be cheaper to make lithium cells safer rather than develop new technology.