That also depends a lot. Often (e.g. on Fairphone) the stock ROM may lag behind way worse than e/OS.
So if a user has reasons to avoid a Pixel, or just wants to improve their privacy without replacing their device, e/OS may be a marked improvement even on security.
an app that require a device integrity in a rom with gapps, just run from beginning in eos (although eos only passed basic integrity, interesting)
a ride hailing app that iirc use google maps, now use (openstreet?) map but the app use an amoled dark theme map (black). in another app, they use light theme map
not all paid apps works, even with the usual workaround of repurchase and cancel