Looks like I’m wrong as always.
There's a WG ambition to electrify to Holyhead.
There have been several studies of the business case, and the recent Union Connectivity Report has recommended further study.
But there are serious problems with the idea.
The limited inter-city service (less than hourly) in North Wales does not support the case. There is minimal through traffic to Dublin these days.
Local/regional traffic is non-electrified, without also wiring to Warrington/Crewe, Shrewsbury, Wolverhampton and Newport.
HS2 has resolutely refused to put Chester/North Wales on its services map, as they don't want to fund the necessary electrification for through services.
So London services will not use HS2 and will stay on the slower WCML.
The most likely extension of the wires is from Crewe/Warrington to Chester, but even that is regarded as "too hard*", and is way down the priority list.
So there's little prospect of wires west of Chester until that issue is addressed.
There are local government bodies working together on this (Cheshire/Wirral/NE Wales) but they don't have serious funding for major enhancements.
There is a draft plan to improve capacity at Chester (eg a new platform 8 to get Merseyrail out of P7).
And as has been said, rail infrastructure in North Wales is not devolved.
Projects which the WG did have a hand in, to increase line speed in North Wales, and redouble Chester-Wrexham, went off half-cock at best.
They didn't fund the Halton Curve project which brought back through Wrexham-Chester-Liverpool trains.
* part of that is down to the way the railway was originally built, with many low arched brick/stone bridges needing replacement.
Ironically the North Wales line as far as Llandudno Jn is in better shape for wiring because it was at one time mostly a 4-track main line with better structures.