Article here: https://phys.org/news/2017-10-scientists-assumptions-planet-formation.html
They accept the assumption that planets are remnants of star-formation. There is no proof that planets are remnants of star-formation. So, I find it strange that the headline to the article states,
Scientists question assumptions about planet formation
"Senior Lecturer in Astronomy at the School of Physical Sciences, Dr. Helen Fraser, says, "We are already aware of thousands of planets orbiting stars in our own galaxy, as remnants of star-formation, and yet there still isn't a model anywhere in science that can explain exactly how planets form. Our basic understanding is that small particles stick together, building bigger particles, which then also stick, and so forth, until eventually, we have a planet."
The assumption they refuse to question is, "are planets remnants of star-formation"? The answer is NO!
Planets are stellar remnants! They are the remnants of stellar evolution, in effect, they are the highly evolved stars!
All the evidence (future, past and current) points to stars in all stages of evolution into life hosting planets, which eventually die and wander the galaxy. Calling the evolving stars, "planets" is where they are wrong. So totally wrong. No wonder they don't understand how planets form, and do not have any working model of planet formation!
What is more troubling is how deep they live in Plato's Cave. They also say, "and yet there still isn't a model anywhere in science that can explain exactly how planets form."
It is completely false. The theory already exists. It is called stellar metamorphosis.