Those seem like relevant factors, and I'm sure there are lots of others, such as that some countries have compulsory voting, and Americans are responsible for registering themselves to vote.

But one factor, as shown in polling below, is that Americans are disillusioned in their system, partly, I suspect, for the cultural reasons I gave, but also because lots of Americans don't follow politics at all. This weak sense of citizenship seems like an effect of individualism. Americans are on their own and don't trust in an all-powerful central government.

https://projects.fivethirtyeight.com/non-voters-poll-2020-election/

https://www.npr.org/2020/12/15/945031391/poll-despite-record-turnout-80-million-americans-didnt-vote-heres-why

https://www.npr.org/2018/09/10/645223716/on-the-sidelines-of-democracy-exploring-why-so-many-americans-dont-vote

https://www.pewresearch.org/fact-tank/2020/11/03/in-past-elections-u-s-trailed-most-developed-countries-in-voter-turnout/