Late arrival of the plane inbound from San Francisco caused our flight to be delayed 1 hr 45 min, causing missed connection. United did move us to a later flight, after another 4 hour layover instead of a 90 minute layover. Air travel has lost its appeal but there are no other options. The plane held 52 passengers, United asked for 3 people to volunteer to go on another flight because the plane need more fuel so couldn't seat a full plane. Really, who makes a plane that can't fit people in the seats and a tank of gas. Flight was good once we did leave, attendant, only 1, was rookie and made several errors, nothing major, but not very good to have the passengers correcting her, could have used more trading or support, she said her first flight to Canada.