I'm sure there are exceptions, but engine problems are way, way less common than the accepted degradation of batteries over their lifetime. Most car engines keep working well even after running 100-200k kms. There is no "accepted" degradation into uselessness as we have for lithium batteries.
The same degradation happens with ICE engines - they lose power and become less efficient.
And batteries which are thermally managed (ie anything but an old leaf) will have a better lifetime than a typical ICE engine -tesla easily achieve 300k miles with less than 10% range loss.
