This will directly stop Irish based people shopping on Amazon as the Irish Amazon is useless and everyone buys from Amazon UK. These fees are going to change that big time so it’s not all in favor of Amazon
If Amazon was competent and saw that as a problem (doubtful, given how hard it is to filter items that actually ship to your country, as opposed to claiming to do so but then on the checkout page tell you otherwise), they could likely bulk-import the items to Ireland, then ship from there.
I assume Aliexpress is ~~going to do~~ doing [1] exactly that to bypass the 3 EUR fee. I wonder if the packaging rules are a shortsighted attempt at sabotaging Chinese sellers without making it obvious.
I agree that amazon.ie is useless, but i think that Irish shoppers will still buy from Amazon UK for more expensive items, where the €3 fee is relatively insignificant. Amazon UK, even with the new €3 import fee, is still cheaper than local Irish retailers who take price gouging to new levels.