The Supreme Court ruled many decades ago that citizenship is a question for other nations to decide. The US cannot tell Ireland (or any other country) who is a Citizen of Ireland. If they recognize you as a citizen, then you are. You can even vote in Irish elections and not lose your US citizenship.
Whether this is a wise choice, and whether this will give you any tax benefits, is and entirely different question. You can renounce your US citizenship but it’s not as easy as it was and with many tax treaties it may not work the way you hope. Not to mention, the USA is the best country on earth. Consult many attorneys and tax experts. You may have an easier life just paying the taxes, stay American, and live as an expat. With Bitcoin or any asset, you can sell just enough to cover your taxes and moving and some time living expenses, then figure out how to handle the rest later.
I don’t know the answer, but maybe you can trade BTC for other assets of equal value without a tax? Would it be a barter? Like a tax exchange? Eg if you traded a house here for a house there of equal value is there any tax implication? Can you do the same with BTC? Or did the laws change in some way?
Nope. Once you exchange crypto for fiat, other crypto, or another asset you are subject to a capital gains tax - currently 38%, but who knows what numbnuts will try to raise it to.