Issuers effectively do need to offer 3D secure, since they are liable for all fraud that happens on 3DS-enabled transactions. It's just their choice on whether they choose to require authentication at all, some, or no transactions.
The US has more of a free market approach here, and experience has shown that the conversion rate hit is often much more severe than the reduction in fraud. Consumers will just use the most convenient card, and that turns out to be the one that just lets them buy (almost) everything without additional challenges.
The EU is taking the approach of forcing all issuers to challenge cardholders for most (higher value/risk) transactions. Given that the rules are the same for everyone, cardholders have nowhere to "escape" to – and issuers finally were forced to invest into making their implementations more usable.
The US has more of a free market approach here, and experience has shown that the conversion rate hit is often much more severe than the reduction in fraud. Consumers will just use the most convenient card, and that turns out to be the one that just lets them buy (almost) everything without additional challenges.
The EU is taking the approach of forcing all issuers to challenge cardholders for most (higher value/risk) transactions. Given that the rules are the same for everyone, cardholders have nowhere to "escape" to – and issuers finally were forced to invest into making their implementations more usable.