North Wales Coast Sunday timetable - why so different from weekdays?

[Bletchleyite]

I originally thought it was engineering work that had caused this, but having checked it's not.

Why is the Sunday service pattern on this route so different from the weekday/Saturday one? On weekdays/Saturdays the only through services to Crewe are the Avanti services, but on Sundays it's basically an hourly Holyhead-Crewe (with a couple of Manchesters I think), some by Avanti and some by TfW, plus just three Holyhead-Cardiffs.

This is quite useful getting back from a weekend away to the South East as it drops a change out, but it seems odd that the Sunday is so similar to the pre-devolution timetable yet the other days have changed almost unrecognisably.

 

[Llandudno]

The north Wales coast timetable is totally inadequate not just all day on Sundays with only an hourly frequency after a lateish start but also only one train per hour on Saturday evenings which does lead to severe overcrowding and a quite unpleasant travelling experience!

The Llandudno Junction - Llandudno shuttles run approx every 30 minutes on Sundays, but the mainline is only hourly…!

Well, I say hourly, nothing is ever clock face in north Wales!

 

[Bletchleyite]

Well, I say hourly, nothing is ever clock face in north Wales!

It's such a simple line I don't entirely understand why it isn't perfect clockface, though Avanti do mess it up a bit. If the WCML as a whole can be very close to that...

 

[LNW-GW Joint]

The line still suffers, like the Marches, from multiple manual boxes with limited hours, despite half the line now being signalled from Cardiff ROC.
The lack of through services on Sundays goes right back to BR days, and ATW didn't try to fix it, nor TfW since.
Maybe something to do with Sunday being in/out of the traincrew working week (hasn't that recently changed?).