IRAs and 401k's are tax advantaged retirement plans. I doubt sheltering them from taxes forever was part of the design objective. Besides, RMD at 70.5 is just, what, 3.65%? Even when you're 90, RMD is just 8.77% and at 100, it's 15.87% (Table III Uniform Lifetime).I think 401k's and IRA's are enablers. BUT, they have major limitations that hold some folks back from their full saving potential in tax deferred accounts. e.g. annual contribution limits and RMD's at 70.5. The government seems to want you to save, but not too much or for too long.
My primary issue with 401k's is not everyone has access to one and the current limits for IRA are woefully inadequate. Another thing, unlike 401k contributions which are salary reduction, traditional IRA contributions may be subject to state and local income tax, and depending on income, may not be deductible for federal tax purposes. The limited (often high expense) investment choices can also be pretty detrimental to portfolio growth.
Instead of having companies set up their own separate 401k plans, why not just have everyone switch to IRA, increase IRA contribution limits (mayhaps $50K combined limit for employee+employer contributions or up to 25-50% of gross income whichever is smaller) and make traditional employee IRA contributions salary reduction similar to 401k? Maybe follow SIMPLE IRA rules for vesting of employer match.