My parents were of modest means, but they set aside some money for 18 years to help me with educational expenses. Not only did it help me graduate debt-free, but discussing what my education fund was doing as I was growing up left me much more comfortable than most members of my generation handling finances.

The only tax benefit is if your state offers one for 529 plans.

Not true. Realize capital gains each year in a UTMA account up to the kiddie tax limits. File a return for the kids instead of putting their gains on the parent's return. It can be significant over 18 years.

Thanks for the correction! Although, would this make a difference if you were just investing in an ETF and not selling and then gifting it to the child, assuming it’s less than the lifetime gift tax exclusion?

While you held the ETF you would be paying income taxes on the dividends at your marginal rates. If the kid holds it in a UTMA some of those dividends would likely be taxed at the lower kiddie bracket.

Agreed, the step up at death on the cost basis would be advantageous but then you have to be dead.

I live in Denmark where the first 10k USD capital gain is in a lower tax bracket.

And there is a scheme with yearly taxation of unrealized gains, but at a much lower rate. However, it has a per-person cap around 16k USD.