Really? We observe other solar systems forming?
How many "theoretical models" are there? Do you believe in one of them, or all of them?
Theoretical models are just that. They are not evidence.
ML/NJ
They have predictive value or are discarded.
For example the theoretical models made predictions for this experiment.
If the data don't match the models are updated to reflect the new evidence.
Just like the interpretation of the Bible. In past days it was interpreted literally to state the earth was the center of the universe. That has been proven false. Smart Christians updated their interpretation, dumb ones updated their interpretation some time later.
In past days it was also interpreted literally to state God created the earth in six days. That HAS BEEN PROVEN false (Absent mental gymnastics like god did it in six days but left millions of years of fossil record as a test of faith. Note that's not the same as proving alternate explantions true). Smart Christians have sense updated their interpretation. Dumb ones are still struggling with this one.
We've seen accretion disks at other stars. Beta Pictoris is probaby the best-known example, but there are many others.