My take
So I’ve experienced this over the last year since travel has begun to cold back. I believe united has no motivation to offer cheaper fares as planes are booked solid with limited capacity
the other issue is this. With no change fees just book the flight. If it comes down closer to departure just change the flight or cancel and use the travel credit to rebook. I’ve done this about 10 times in ve the past year. With the removal of change fees I think it’s completely thrown their revenue model into a new world