80 years? Come off it. Fantasy again. Ireland joined the EU in 1974 I believe. There's a pretty decent case to be made that 1974 would be the date on which Ireland's economy started to speed up to eventually zoom past jolly old England's.
It seems a perfect role model for Wales. Facing an economic catastrophe conjoined with Brexit England versus independence within the EU is no dilemma. Choosing the latter is a no brainer.