What is a congestion charge in this case? It sounds more like a traffic/road maintenance thing than related to emissions?
Most places I've lived (US and Canada) only require emissions testing if the vehicle is old enough not to have modern emissions control sensors. The test costs maybe $20 every couple years, which is nothing compared to all the other costs of owning a vehicle.
Presumably your 2010 Polo doesn't have a check-engine light if the catalytic converter has a hole in it, but your 2021 4x4 most certainly does.

Edit: (See comments below about emissions systems).

Specifically Washington State only required emissions testing (tailpipe test on a Dyno) on model years 2008 and older, after which the only requirement is California's "CARB certified" with no testing other than at the factory. And as of 2020 they don't even do emissions testing anymore.