MDF2, I agree with you - I have a whole office full of people who all rely on the ability to customize what columns you can see, to move them and to sort easily by that column by clicking on it directly. Result: we are not upgrading to Catalina. I personally know 14 Mac users in a work environment (and more who are personal users) who rely on this feature, and can only imagine that other professionals in office environments also do as well. As a 16+ year iMac and MacBook Pro user in a professional environment, I hope and believe I have a voice.
The biggest problem for our office is we communicate with clients and each other on emails addressed to a person (or persons) and cc:d to many others - this is because everyone needs to be kept in communications loops, but not all have an "action item" in an email received. By seeing the "From" field, I know who is sending the email and using the "To" field beside it, can see all who are in the loop. I myself am able to quickly and efficiently prioritize my day by knowing what emails require my personal immediate attention and what is an FYI for me - at a glance. I am also able to see who has been included and that they are up to date. I am able to prepare in advance for tasks I will be hit with and make sure all the info I need to succesfully complete those tasks is available to me.
I get anywhere from 50-80 or more emails every day in 3 different email accounts. Mail is only 1 of a few apps I use to keep on task and productive and the "From" and "To" fields are critical to my work day (along with folder sorting, flags etc.). And Catalina requires me to open up each and every email in order to see what I need to in order to determine where that email is in my priorities - it's hobbling my efficiency!
William, this feature is useless to you, but please respect and realize, it IS very important to many many people..... as the sheer volume of entries in this forum illustrates. Please do not generalize or put down the frustration that these forum users are expressing.
And for everyone reading - use the feedback url or call and speak with an Apple rep yourself. I have done this and requested it be tagged and escalated for attention - what will result, I can only hope is a return to the features many of us require.
Forgive the long post .... maybe not everyone uses the customization abilities like we do, but I hope I speak up for some! : )