You could say that about literally any shady business. Imagine seeing a PDF proving tobacco leaders knew for decades that it caused cancer and saying what you did.
Being monetarily successful does not mean you’re good or shouldn’t be criticised.
Are Marvel films shady for being popular? Is HN shady for adding features which increase engagement?
You don’t think this is optimized for for engagement? Don’t let the beige design fool you.
Instead look at reddit is desperately trying (inline ads, chat, avatars, forcing app use)