Usually when unticking this box when saving a pdf, the file size would greatly be reduced. A 1gb file down to 200mb ish. Or a 50mb file down to 5mb meaning its easy to send to customer by email. This is no longer the case, it make zero difference to the size.
I'm having to use Illustrator 2024 to do this as the last update to 2025 stopped it working and 2026 doesnt work either.
Luke