(a) Yes, they are low (b) No, that is just an urban myth.
The corporate tax rate for corporations engaged in active business (what they call trading income in Ireland) is lower than the rate for a similar business in Canada or the USA. For example, the rate in Canada is 27% combined in most provinces and in the USA it is 21% federally and then states taxes that vary from 0% to 3% are added.
However, it is hard to compare apples to apples because every country has different systems to encourage different segments of the economy. For example, in Canada, a “Canadian Controlled Private Corporation” can pay just 11% on its active trading income.
The moral is that you have to hear all the facts before you decide who truly has a lower tax rate.