I commuted by train on Manchester local services 1973-1980, and there were many stopping services and very few fast services during this period. In my case on the Macclesfield line, and from the 1974 timetable change there were stopping services to Macclesfield or beyond in the evenings at
15:53, 16:10, 16:43, 17:02 (omitted Adlington), 17:15, 17:30, 17:43, 17:58
whereas the only fast services were at
15:35, 16:23, 17:12, 18:28
Nowadays there are far more fast services, and the stopping trains are hourly with one additional rush-hour service which gets overtaken by a fast service at Macclesfield.
Essentially in the earlier days of electrification there was a lot of commuter traffic which doesn't exist any more.
The Wilmslow service (where I now live) was every 15 minutes off-peak, with additional peak services. Admittedly the service beyond Alderley Edge (Chelford and Goostrey in particuar) was thin and Sandbach is now a busier station that it used to be.
But the investment in local stations and stopping services was sensible back in the 1960s and 1970s, it's only since 1980 or so that the commuter traffic has fallen away. The commuter trains of the 1970s that I remember were full - I groaned when I saw 001-015 on a service I caught at the last minute because it probably meant I had to squeeze into one of the compartments.
I have to say that the unreliability of today's services would make me think seriously about driving to work instead, if that were an option. My father and I did that briefly back in 1980 because for two of us it made sense (until then my train fare was paid by Cheshire County Council). But back in the 1970s the commuter trains services could be relied upon in a way that they clearly can't be today - cancellations were almost unheard of. Today's commuter service is complete pants in comparison.