Been on there for 15+ years, and have contributed to the wiki myself. It never stops being relevant.
-- -----
Like over recent years I went from being independent to being an employee. We have a 401K with a good match, but the TDF choices were subpar. Good asset allocation and underlying funds, but they only offer the $0 minimum versions which are 0.75% ER, whereas the $3000 minimum version (it's a tech company, people are putting $3000 in no problem!) would be 0.12% ER.
Most people would put in the TDF and call it a day, which I wouldn't fault them for -- keeping it simple is what reduces friction and gets people to contribute earlier and contribute more. Except if you were there for 30 years, maxing your 401K and match every year, you'd be eating at least an extra $300,000 in expenses. Compound interest works both ways, after all.
The better solution? I will eventually petition HR to also add the Investor Class TDF options, but for now I instead simply rolled my own 4 fund portfolio with the remaining options to hit the same asset allocation, with damn near identical holdings. Took a few hours of research and making a spreadsheet with two or three very simple worksheets. All basic arithmetic.
I didn't just go from 75 basis points to 12 basis points: I ended up at 6.4 basis points. By comparison, a Vanguard TDF is 8 basis points. I'll re-balance it and adjust my contributions once a year, spending 5 minutes punching a few numbers into a spreadsheet to then punch corresponding numbers into the custodian's website. Set a reminder so I'll do it every year. Easy enough, and I reduced my expenses by ~91.5%.
If you nerd out and dig deep into the Bogleheads wiki, this kind of stuff becomes A) increasingly obvious and B) increasingly easy to recognize these opportunities.