That's my point, there's a huge difference in tax implications. You can sell losers/duds/underperformers to raise cash while allowing winners to compound tax deferred.
If you've got $10 million in a taxable investment account and want to take out $400k a year, you could be paying 37% in a high tax state just on long term capital gains, so tax loss harvesting does have value. You'd probably need a lot more than $10 million to really make this worth your time, and there are direct indexing services available, haven't really looked into them.