ZH's Sunday article on this had a good point, emphasis mine:

Launched in 2017, Zillow's iBuying arm uses a wide array of real-estate data with the goal of quickly and efficiently acquiring properties to flip for a profit. The program has vacuumed up properties across the country to flip, only to be met with fierce competition from services such as Redfin, Offerpad and Opendoor. And according to iBuying analyst Mike DelPrete, Zillow's competitors aren't having the same problems - with Opendoor's median home priced $4,400 above what they paid (which, quite frankly, is also pretty terrible).

• https://www.zerohedge.com/markets/zillow-caught-holding-bag-93-phoenix-flipping-portfolio-listed-loss

'Terrible' is probably an understatement.