Less now, for sure, but you're overlooking a major category.

Many of the really bad mutations are embryonic-lethal, which is why a surprisingly high proportion of pregnancies "don't take" or end in miscarriage.

Yes, and many more cause carrier mutations that won't surface until the next generation, or late-onset metabolic or neural disorders that will cripple the individual later in life, or increase mutational load resulting in much higher chance of cancer. The fact that some mutations are benign and others fatal really doesn't change the issue that we don't yet know how to safely edit the human germline.

Totally agreed--I think this was a horrific and stupid thing to do.

I just wanted to push back a bit on the idea that medicine is badly "breaking" evolution by keeping people alive.