Yes, and longer videos allow for Youtube to insert more ad breaks. For viewers that are Youtube Premium subscribers, the revshare portion that goes to the creator also grows linearly with watchtime.

Additionally, "the algorithm" rewards channels that have a lot of watchtime & retention (because againg, this leads to more ad placement opportunities for Youtube). So if you are able to produce long-form videos that keep the viewers engaged and watching, your videos are more likely to be recommended, which reinforces the popularity of long videos.