Looking at last year marketshare, it's not that Switch does poorly in EU, but with PS4/XBO being interchangeable in many ways, it has more to do with the Xbox brand being relatively strong in the US but weak in EU.
US 2018
NSW-5.58m (36.8%)
PS4-5.28m (34.8%)
XBO-4.31m (28.4%)
EU 2018
NSW-4.48m (33.1%)
PS4-7.47m (55.1%)
XBO-1.59m (11.7%)
As you can see, Switch had similar marketshare in US & EU last year, the difference is that the PS4/XBO battle is competitive in the US while in EU it's an absolute bloodbath.
When the herd loses its way, the shepard must kill the bull that leads them astray.