Most of this recording business is new to me. Bear with me and my dumb questions...
If I've got multi-track recording software like Reaper, why would I buy a mixer? Can't I just do the mixing on the computer?
You can only record 1 take at a time with a single input. With a mixer, you can record multiple inputs to multiple tracks if you have the correct setup.
For instance...I'll record my acoustic guitar direct and also with a mic. Then I'll mix the 2 tracks together in the software.
I can also record guitar, drums, and vocals at the same time and then mix them on individual channels in the software.
A mixer is pointless unless you have a way to stream each input to a separate track within the audio program.
If you're a solo act or don't plan on recording multiple inputs at the same time...don't buy a mixer.