One point I didn't mentioned in my article about the multiple of similar ETFs is the tax benefit, namely the wash-loss rule.
The wash-loss rule is intended to prevent people from selling a position for tax benefits and then rebuying the same position within 30 days. While I don't really get the whole point anyway as the cost basis will be changed, it does make it annoying for people who have multiple accounts as it does mess up holding the same position in multiple places.
That's where the beauty of similar ETFs come in. Instead of buying SPY in both accounts, you can have one with SPY and the other with VOO or IVV instead.
Of course there's an inefficiency in return from doing that but it does simplify and avoid wash loss issues as they're not considered materially the same holding (as opposed to derivatives who are).
Anyways, just a bit of a minor tip.