Hmm... well back in Sept 2018, the R House passed a bill to introduce Universal Savings Accounts (USA).
It operates similar to a Roth IRA, in that it's funded with after-tax money, no tax on gains, and limited contribution per tax year (a mere $2.5k). The difference is that this account can be withdrawn from - contributions and earnings - with no penalty, and no age restriction.
It is still waiting to get in to the Senate... and for the Presidential sign-off to make it law.
This was generally a Republican supported bill in the House, so hopefully it should have no trouble passing in the Senate. It just needs to get on someone's radar..
The only media opposition I've read about this piece of the bill is complaining that it mostly will only benefit middle to upper income households that can afford to set aside 2.5k per year(!), and that the plight of low savings among low income workers is a systematic issue of the economy which this won't really address (due to paycheck to paycheck style living).
Personally, I am openly supportive of a bill that would reduce household tax liability and provide a natural, emergency fund buffer for people, which is beneficial to the overall health of the economy and for financial household stability.
This bill almost seems tailor-made for Mustachian stashers who can recognize the advantage, and will organize their budget to set aside money for it.
In terms of tax-advantaged funding priority, I would say that a USA would rank very high, right after 401k matched contributions, due to its complete accessibility and tax free gains!