I admire the grit. Although turning down the Developer Support Engineer offer from Facebook to be a SWE at PepsiCo sounds like Jon Snow turning down the Steward role he was offered by the Lord Commander.
Depends on the priorities. I would rather write code all day at PepsiCo instead of writing code 2-3 hours and writing documentation and answering emails in the other 5-6 hours at Facebook. Besides, the transition to an SWE at FB takes 2-3 years.
I believe sometimes you have to take a step back in order to make 2 steps forward later. But I saw that as more than 1 step I had to make backwards.
I wouldn't view it as a step backwards at all. FAANG employees are just about the most pampered workers on earth and they know how hard freelancing can be. Only thing that really matters is having engineer in the title. Everyone does the dishes. Two to three years is like the blink of a eye.