The reason St Patricks Day or St Andrews Day has more resonance in those nations than St Georges Day does in England is because they are celebrating their identities formed in resistance to an 'other' in their case... England.
Celebrations here still have a subtext of imperialism

If it was just drinking ale, eating roast dinners, folk music and reciting William Blake. I honestly wouldn't mind that much cause I like those things. But the reality is it's not and it's not what is celebrated by most people participating in it.

Going on about "not being ashamed", hyper-defensiveness and needing to be better than everyone else but not really knowing why. Blaming everyone else (foreigners, POC) for feeling "ashamed" to be English when the people who made it shameful in the first place are in fact English.

Even the imagery that's mostly used of St George is him as a soldier about to go to war. St Andrew has a fishing net and St Patrick, if you spot him at all amongst the leprechauns, is driving out snakes. Very different energies there.