The decreasing level of returns from portfolios with sensible amounts of risk just underlines that to bank on 4% return whether it's from an income or total return approach is itself increasingly risky. The drift of portfolios towards higher yielding bond and dividend funds has lots of danger. That's why I'm glad to have 50% of my ER income requirement covered by rental income. When US SS, UK state pension and my deferred annuity kick in the performance of my portfolio will be irrelevant as far as income generation goes as rental and those fixed sources will cover my needs.
Investment companies are obviously going to talk about strategies that use the products they sell and the video with the Vanguard analyst has lots of good information, but there are other options. I chose to buy a two family house and pay off the mortgage asap to reduce my need for income and so it would also generate net income every month. I also chose to voluntarily contribute to the UK's equivalent of SS. At the time many people thought I was stupid to pay an extra tax, but it's been a great "investment".
As ever diversification is important, and that doesn't mean just equities and bonds. FYI my AA is pretty simple, 32% Total Bond index, 21% total stock market index, 20% "psst", 11% international index, 6% TIAA-Traditional (deferred annuity), 5% bits and pieces of old REITs and emerging markets, 5% cash and I'd favour a total return approach to income as I'm an indexer at heart.