While it states "Other electric cars inspected", it does not appear to specify if that means simply all other electric cars, or other electric cars with the model year 2020. The latter is the only group that should be compared with the 23% figure.
There is a small note explaining that the Model 3 was introduced in Denmark in 2019 (MY 2020), and therefore 2024 is the first time the M3 has been called to the routine inspection (periodiske bilsyn), hence the specific focus on that model year for this article.
(Weight is a factor but lots of electric cars are similar weight to lots of hybrid cars so it's something to keep in mind no matter what and not a particular reason to exclude hybrids.)
Which is not surprising, since Toyota now has almost three decades worth of experience with the Hybrid Synergy Drive system, and double that experience in building reliable cars in general.