As of 2023, electric bikes (the type with electric support up to 25 km/h) are mainstream in Central/Western Europe.
More than half of newly sold bikes in Germany are electric, with the trend increasing. Anecdotally, when I'm cycling in hilly areas in central Germany, the large majority of touring bikes or mountain bikes are electric. My estimate in Odenwald or Spessart is that more than 90% have electric assist. It makes going up a 10-15% slope a lot easier, in particular for older people, who otherwise wouldn't be riding there at all. Only road bikes remain mostly/overwhelmingly pedal powered, which makes sense, because riding a road bike is about sport and perhaps competition, whereas touring or commuting may be more about getting somewhere or enjoying a day out (and for this reason, there aren't many electric road bikes out there). Among freight bikes the market share of electric bikes is even higher.
There may still be places in the world where regulations are lagging behind, and they remain much more expensive than regular bikes — but they have clearly and definitively arrived in the mainstream.