The linked comic talks about underpaid factory workers in China - every company that sells smartphones suffers from this to some extend because tracking down supply chains many links in becomes very difficult. It is not so easy to determine with 100% certainty where the guy that sold you the refined metal for the CPU chip got his unrefined metal from. Apple has actually made big efforts in attempting to eradicate slave/child labor [1] - so if you care about human rights of labourers in third world countries you should probably buy an iPhone.
None of this is black and white, both Google and Apple have tons of problems. If you say "don't buy Apple if you don't support walled gardens", then someone else will say "don't buy Google if you don't support extensive privacy invasion". There is no correct choice - you can only fight the specific problems.
[1] https://www.voanews.com/archive/apple-wins-global-award-effo...