One of the hurdles to getting more bystander CPR was aversion to ventilations. The criticality of consistent, continuous compressions was already known. AHA, ARC, and the medical community made peace with the blockers and rewrote some lay curriculum for compressions-only. They also created some options for familiarization/completion courses instead of certified courses that didn't require portions of the usual testing, increasing the amount of people willing to take the class at least have the knowledge in a credible way.

Certification courses that include ventilations and barrier devices are still the standard of care for medical personnel and professional rescuers.
Properly performed ventilation+compression courses in general are still better than compressions-only.
Rescue breathing is a critical skill in infant/child products.
Ventilations haven't gone away, they are just made optional/deemphasized by training product. Anyone that says otherwise is wrong.

Another factor in this is access time. Compressions-only is most viable where there is fast access to rescuers. In areas of delayed response, ventilations become important again for everyone. However, even then the longer you're doing even good CPR the lower chances of survival are.

Contents of various training products are available the ARC, AHA, and NSC websites.