Over 152 million votes were cast, representing more than 64% turnout among those eligible to vote (https://en.wikipedia.org/wiki/2024_United_States_presidentia...).

The USA has about 342 million people, and over 18% of them are age 14 or younger (https://en.wikipedia.org/wiki/Demographics_of_the_United_Sta...) and at least some of them are 15-17 (citation needed). So clearly, doing some arithmetic, there are fewer than 304 million adults.

Not only was "half the country" not "disenfranchised", literally a majority of adults actually voted (and this is not even considering that not all adults were statutorily allowed to vote in the first place).