> Compared to ICEs, where advancement has stalled for the last 20 years,

It hasn't really stalled: VVT, VCR, Cylinder deactivation that works properly, and start-stop becoming commonplace are all meaningful improvements (though smaller than the ones seen in EVs over the same time frame, which makes sense given the relative maturity).

ICE advancements haven’t materially affected car performance like EV advancements have. Start-stop is considered an annoyance to most car owners, for example, not a feature.

It is mostly because ICE tech is mature and has no real place to go for improvements beyond incremental refinement. EVs can ride the wave of battery tech advancements for another decade or two.