Why does Bootup.php run with PHP 5.4.16 from with Craft script but PHP 7.4.10 from the terminal command line?
Where did you define your aliases? If you haven't already, you could start by adding directives for both php and composer in your .bash_profile.
The file should contain something like (alter paths as appropriate):
# Include the location of the PHP 7.4 binary in your path
export PATH=/opt/plesk/php/7.4/bin:$PATH
# Ensure that any calls to composer are run with the PHP 7.4 binary
alias composer='/opt/plesk/php/7.4/bin/php /usr/lib64/plesk-9.0/composer.phar'

Log out/in (or source .bash_profile) and run php -v to check it's picking up the correct binary, then have another go.