Problem migrating to localhost

As in this question and answer, and because of your huge .htaccess file it’s like you have a .htaccess directive that’s causing your apache to not process that file or understand its type.

As mentioned by @Rup, using the default WordPress .htaccess, and checking other directories for rogue .htaccess files will likely resolve this issue.

If it doesn’t, you need to check how apache and this particular vhost are configured as it’s likely you’ve got a rogue .htaccess file or directive causing apache to not be able to process PHP