> If the value of your shares goes up, you don't get taxed that year. Instead, you get taxed whenever you sell, which might be later when you retire and are in a lower tax bracket, or after a period of some years when you get a lower capital gains tax rate.

This is actually not true in the Netherlands, which taxes unrealized gains on wealth. Quite unique. But NL also features a dividend tax, which politicians tried to get rid off but didn't succeed because it was such an unpopular plan.