It doesnt have to be - bigger battery strictly-series EREVs would likely show better numbers than the weak-ev phevs sold today.
PHEVs in a world that includes externalities in the cost of fuel will be used in EV mode more. Same vehicle different outcome.
Currently it's a mishmash with some countries penalizing electricity use while subsidizing fuel sales in lots of different little ways.
In general it's trending in the right direction though.
EREVs are a different story, and have a place in the transition for awhile.
This doesn't make them terrible! This makes them great. That means they can run 80% of the time as an EV, yet use the ICE just enough to not ever have stale gas in the tank. As a driver you barely notice, and someone outside will have no clue what mode it is operating in. (wind noise is louder than the ICE)
When there are fast chargers on every corner like gas stations are PHEV will make less sense. However in the world I live in today an EV can do a road trip but it forces you to plan your stops around where there is a charger, while with gas can still assume it will be close when you need it. This will change over the coming years, for now I won't take my EV on a road trip, but my PHEV has done it several times.
they dont though. Real world data shows it indeed makes them terrible.
https://electrek.co/2026/02/19/biggest-study-yet-shows-plug-...
https://www.electrive.com/2026/01/23/year-end-surge-electric...
For most in the US what makes the most sense today is one PHEV they use for long trips and towing the boat. The rest should be pure EVs, which have enough range for the typical trips and the few exceptions they just reserve the PHEV that day. As time goes on more and more chargers will be built and eventually pure EV for everything will make sense, but right not there isn't enough charging infrastructure. (You can get almost anywhere in the US, but the trip is planned around where the next charger is, not where either you feel like stopping or where the battery is low - gas stations are at nearly every exit, fast chargers 1 in 30 exits or something in that range)
And across Europe BEVs are also about twice as popular as PHEVs. In 2025 2.6 million BEVs were sold in Europe compared to 1.3 million PHEVs. It seems the biggest deciding factor is how good the public charging network is.
Sources:
https://bilmagasinet.dk/bil-nyheder/hvor-mange-elbiler-er-de... (Danish)
https://bilmagasinet.dk/bil-nyheder/saa-meget-steg-salget-af... (Danish)
https://www.tradingpedia.com/forex-brokers/global-demand-for...