FTSE100 offers many important observations/insights, but in this blogpost main focus is dividend stock picking.

https://www.hl.co.uk/news/articles/how-different-are-the-s-and-p-500-and-ftse-100 says

the FTSE 100 includes a lot of banks, oil companies and miners. These companies tend to be quite cyclical meaning they’re closely linked to the economic health of the country and tend to follow the ups and downs of the economy. They generally don’t have a lot of room for explosive growth. …  The S&P 500 trades on a price to earnings ratio of 22.2, which is much higher than the FTSE 100 – currently trading on a PE of 14.4. Additionally, the historic dividend yield on the S&P 500 is 1.8%, compared to 4.8% for the FTSE 100.

— DRIP
Note most comparisons of FTSE100 vs SP500 graphs ignore dividend. It is hard to verify but some authors say that DRIP would dramatically change the picture.

— hot tech stocks [hot money, low CDY] has a huge presence in SP500
I think four articles comparing FTSE100^SP500 (or DJIA) all singled out this as the biggest of many reasons for the superior 10Y performance of SP500.

Coincidentally, Vance of DBS said the Singapore STI suffers the same weakness. “Sunset industries”.

— survivorship bias and natural selection ..
If we compare two ETFs tracking FTSE100 vs any tech-heavy index, we need to ask which index is adjusted more often. Tech-heavy, frequently adjusted indices tend to benefit from survivorship bias and natural selection. If no adjustment allowed, then the fatality rate (of tech stocks) becomes more apparent.

I guess (without evidence) that a tech-heavy index ETF would buy low sell high more often, due to index adjustments. The passive ETF manager would follow the index, to swap out laggards and swap in rising stars.

This blogpost is about indices, but here is a digression. ARKK and TRBCX are more tech-heavy than SP500, and more actively managed. I don’t have the bandwidth or skill.