the european perspective is obviously very different from what those of us in north america see. 3 million ebikes sold in europe. only 400,000 in the united states in 2018. it would be safe to assume it doubled or more than doubled and that number is closer to a million now but still well under half.
again looking at the 2018 data, the top three in the US were trek, specialized, and electra. since 2018, trek has purchased electra, and it's worth noting that several of electra's best-selling models are in fact rear hub drive. (e.g. the townie go! 7d.) so, for north america at least, it's not correct to say that the biggest players only sell mid-drive bikes. they *mostly* sell mid-drive bikes. trek claimed $200 million in e-bike revenue in 2018, which at an average price of $4k is 50,000 eBikes.
vanMoof sold approx 40,000 bikes in 2020, so while they're smaller, they're not that much smaller. perhaps half the size assuming various amounts of growth from 2018 to 2020 and split of north america vs rest of world. the distribution of their sales is clearly VERY skewed; after RAD, they are probably the most common e-bike i see in san francisco other than bikeshare and delivery vehicles.
speaking of Rad, they claimed $100 million in revenue in 2019 and that it "spiked by 300% year over year in april 2020." assuming there's some optimistic accounting there, that's $250 million in revenue for 2020, which makes them bigger than trek was in 2018. so, again, in the north american market, i wouldn't be so quick to assume who the biggest players are. Rad's bikes are far cheaper than Trek's, so with roughly similar revenue it's safe to say there are a LOT more rad eBikes on the road in North America than there are Treks, or Specializeds. come to san francisco (a place where the typical road bike is as likely an s-works model as anything!) and you'll see this very clearly. rad, rad, rad, vanmoof, aventon, vanmoof, rad, trek, rad, specialized, vanmoof, specialized, trek, trek, aventon, rad, yuba, rad, specialized....