Websurfer awareness is not the primary reason Vimeo has less viewership.
The cause & effect before the buildup of awareness is the incentives that prevent content creators to upload videos to Vimeo in the first place:
- platform membership fees: Youtube is $0 to upload and host, Vimeo used to be $240 and now has some new pricing plans[1] with a low-use free tier (too limited for high-res 4k uploads)
- no advertising partners : Youtube enables monetization without content creators asking audiences to pay for subscriptions. This financial model covers a wide variety of videos especially for unknown creators.
The financial model of Vimeo is fine but its inherent costs will keep it smaller than Youtube because both the uploaders and the viewers don't want to pay.