When the lane changes were introduced, I didn't think it was a big deal. Anyway I need to press the indicator stack, so in my mind I had minimized the value addition it brought. But over the period of years and tens of thousands miles driving in highways and city roads in Autopilot, I had always used it to change lanes. It worked great as long there were semi decent lanes.
I did not realize how much it added value and enhanced AP, until I started driving my new Model Y (with no FSD package) and boy how annoying it is to cancel AP, change the lane and wait for the steering wheel icon to show up and then engage again. So I end up using AP less when frequent lane changes are needed.
I don't begrudge Tesla for reducing the basic AP capabilities, as they have also reduced the price. I bought my Model Y for less price than the base cost of Model 3 LR (without the $5K AP package when Model 3 was released).