Comment by nic547

I've done the same thing for a few reasons.

- Certain things need good layouts - I think I can see a DC-DC Converter, you need to minimize certain loop areas, etc. You also need to ensure that you use the correct footprints for the chips. Way easier to just use a bunch of modules with a simple pcb.

- It reduces the components you need to aquire - you need to select a inductor with the correct specs for the dc-dc converter, a bunch of different resistors and capacitors for all sorts of uses or you just purchase a cheap module from china.

- It's easier to solder. Fancy chips with packages with no leads are not trivial to solder. LED's might be a bit sensitive to temperature and can get destroyed by a not-so-great solderer. Small pitches on IC make it easy to create solder bridges or bad connections.