All the devolved laws that have been given by the UK Government are ones that the UK Government want to give away, NHS etc. They don't care how the money is used as it's given by the barnett formula which more than likely saves them money in the long run, set up, admin, maintenance etc considering most of the infrastructure is already old.
A huge issue is how HS2 can use Welsh tax payers money as it is a Wales/England railway due to rail not being devolved, this is absolutely criminal as not 1 metre of track will be in Wales. All while it has been forecast it will negatively impact the Welsh economy by £100million per year. I wonder if the devolution of the Valley lines has been halted on purpose so Westminster doesn't have to give any of the 100Billion HS2 forecast via the Barnett formula? Once work has started then the devolution of the valley infrastructure will magically be completed.
In regards to the Assembly, Labour is the issue, not devolution. Anybody in charge for 20+ years will be complacent due to the confidence of being voted in time after time, if Labour get voted out of the Senedd next year they will improve by the time the next election comes around. I was originally a Labour supporter but due to their incompetency I will be voting Plaid next year, I would even prefer the Tories get in over Labour next year if Plaid aren't able to raise enough support as Labour are in need of a wake up call.