Other countries don't have a deemed disposal rule as far as I know. You pay tax when you sell. Do those other countries tax the ETF on their internal gains?
The typical rule is that a pooled investment fund is taxed on its earnings unless it distributes its earnings to unitholders each year, in which case the fund pays no tax but the unitholders, of course, do.
A variation on this rule will allow a fund to go untaxed so long as it gives unitholders a statement of the earnings imputed to their units on which, again, the unitholder is taxed.
If I'm not Irish resident and I buy an Irish ETF, I am not subject to the deemed disposal rule because my country doesn't have that rule. The gains in the ETF are still rolled up.
Depends on the law of the country concerned, obviously. Most of them require residents to report the earnings or imputed earnings from overseas investments. There may be a certain amount of tax avoidance going on, with taxpayers failing to report their overseas investments (Ansbacher accounts, anyone?) but for obvious reasons not many countries design their tax system to tax earnings in domestic funds annually, but allow gross roll-up in offshore funds.
We have thousands of ETFs based here because, I assume, all the ETFs gains are allowed to roll up. Effectively, we have this huge funds industry based here to avoid tax on rolled up gains.
Most of the funds domiciled in Ireland are not marketed to retail investors in other countries; other financial institutions invest in them, and their tax arrangements/tax obligations in their countries of establishment may differ.
The Irish-domiciled funds pay no tax in Ireland on their earnings, but many of them either distribute their earning each year, or report earnings to investors in each year, so that the investors can comply with their tax obligations in their countries of residence. Their may be some that don't distribute, marketed to financial institutions (like pension funds) that are allowed gross roll-up.