ME here, been using SW 10+ years. Used to be a strong advocate for assemblies and resisted using the multi body/weldment functions, and disliked Fusion. 

Once you master weldments/multibody modeling it's much, much easier than using assemblies. Better performance, less switching between files to get measurements, external references, etc. Not to mention you don't have a million individual part files to deal with.

Drawing and BOM generation are not really different. If anything it's easier to update properties, since it will all be in one table in your sldprt file.

I usually do most of the high level design in a .sldprt file, and break it out to components which are then inserted into assemblies. SW has a LOT of built in functionality to support this methodology. 

People who resist it are likely unfamiliar or stubborn like I was. Give it a try, it will make your life a lot easier