> I want the safety and uniformity of knowing that have gone through the review process
Like I said you could choose to install only reviewed apps.
90% of the apps I install on macOS are not reviewed by Apple and after 12 years that has never been a problem for me.
> If it not mandatory, no one will do it and I will lose the protection I have now.
If users prefer Apple-approved apps then the dev market would shift towards that.