The majority of people probably are using tax-sheltered accounts and are primarily saving for retirement, or their kid's education.
If anyone can max out all of those, and pay their cost of living, they're (a) doing quite well for themselves, and (b) probably a small portion of the population.
The advice to not focus on dividends but on total returns is geared toward the general public, who probably don't want to get into the minutiae of tax laws. :)
Maxing out your annual pension allowance - as I said it depends on your personal circumstances, however I think many people on HN mid/late career will have no difficulty there