Cashing out a Roth IRA is a no brainer right?

I’ve read a lot of the discussions here around various retirement investment options, and one of the points is that Japan does not in any way recognise the tax advantages of a Roth IRA.

Therefore before becoming a permanent tax resident, paying the US 10% early withdrawal penalty on the capital gains now is a better option than paying the 20% Japan capital gains tax later. It seems obvious, but is there anything I’m missing?

Edit: It is very clearly not a no brainer and I greatly appreciate everyone’s comments.