>  They're much less expensive, but at a much larger volume

It is precisely because they are much less expensive that they've reached a realistic ceiling of advancement. If you're going to produce an ICE that yields a 10% improvement in efficiency, decreased weight, increased reliability, decreased maintenance effort -- but at a cost of an extra $xxxx per unit, then it may as well never happen.

As a logical exercise, let's consider what are some of the top technological advancements in ICE and ICE drivetrain components over the last 20 years. CVTs? Nissan's VVEL? What do you think are noteworthy automotive ICE technological advancements we can look forward to in the consumer space? Where exactly do you see automotive applications of ICE advancing in the next 10 years?

On the other hand, it seems pretty easy to see the exact opposite with electric/hybrid drivetrains. Many innovations and advancements. It's also easy to see the roadmap for advancements (see what the Chinese are doing). Battery swaps? New chemistries? Solid state batteries? Compact axial flux motors? Faster charging electrical architectures? Endless space for technological advancement and growth because it's so early.