This question has been asked numerous times in the past. There seems to be no settings option, even in the preference file, for determining the amount of image (re)compression on the Mac version of AC.
The recommended options remain:
1. Open the final PDF in Adobe Acrobat Pro, if you have it, and use save as reduced, or optimize options after publishing
2. Open the final PDF in Mac Preview and use Export to export a new copy of the PDF and choose the Quartz Filter option of "Reduce File Size". If you need better tuning of the compression, you can see the settings for that filter and make your own version using the steps here:
http://support.apple.com/kb/PH10577?viewlocale=en_US&locale=en_US
AC 28 USA and earlier • macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB
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