Amusingly at the last election, Lib Dems proposed half price travel for journeys before 07.30. Not exactly helping their reputation as being the party for the out of touch middle classes; it is quite easy to check TfL statistics to see how busy early morning trains are!
Out of interest, what it the best place to find the source of the detailed TfL statistics on how busy early morning trains are ?
Although I haven't been able to track these down, I have found an interesting November 2019 article
TfL published some tables about Tube Capacity and they are amazing on the
CityMetric website.
The background is as follows :
Have you ever wondered just how busy the tube is as you’re sardined in every morning? Or which the quietest tube line is in the depths of night?
Well it turns out that Transport for London (TfL) holds this data and quietly released it a few weeks ago in response to a written question to Sadiq Khan from
Conservative London Assembly member Tony Devenish. He asked about the capacity on the tube and TfL decided to publish the data it has in the form of three excellent tables which I’m sure the audience of
CityMetric will be poring over for some time.
The 'three excellent tables' show tube utilisation by line by hour ;

'over half full' by line by hour:

and 'all seats taken' by line by hour:
To my mind, these present a fairly convincing argument for reducing fares prior to 0730, regardless of political persuasion.
Even considering the four busiest lines between 0600 and 0700, all have occupancy between 30% and 50% higher in the peak hour 0800-0900, i.e.
Bakerloo 0600-0700 64%, 0800-0900 95%
Central 0600-0700 66%, 0800-0900 116%
District 0600-0700 55%, 0800-0900 85%
Victoria 0600-0700 55%, 0800-0900 105%
and in normal times any measure to shift some of that usage earlier would be of benefit. Whether the same applies now, with many office workers working from home is another matter.
It is noticeable from the tables that the two lines with lowest utilisation between 0600 and 0700 are the Metropolitan and Waterloo and City at 25% and 15% respectively. As these are perhaps the most likely to be carrying 'out of touch, middle class' types from Middlesex and Surrey, it would be understandable if they were less aware of how busy other lines were at this time, but i don't believe that alters the argument for reducing fares prior to 0730 to balance the load.