It may be politics, rather than technology, that kills the internal combustion engine.
I think that when electric vehicles become ‘good enough’ and ‘cheap enough’ to be viable (even if still less good and more costly than combustion engines) governments will force / encourage them to the point that combustion engines become seen as old / dirty throwbacks, like steam engines.
And anyone daring to bring facts into the argument like the total carbon footprint of their manufacture, or the number of power stations being built to power them, etc will just be shot down as deniers.
But hey, that’s progress !