There are two factors at work in my opinion. Doordash prioritized selection, they did online ordering even when restaurants didn't want it. Eventually the dema

There are two factors at work in my opinion. Doordash prioritized selection, they did online ordering even when restaurants didn't want it. Eventually the demand was high enough that restaurants adapted. Grubhub focused on the traditional take out restaurants. Doordash also mixed in multi-delivery to handle mixed alcohol/food purchases. Beyond this, tech always follows a power law distribution in returns. Doordash is the number one player, and as such will be about 10x bigger than the next runner up. How much of this is network effects/first preference vs. manufactured return is anyones guess, but most people do not want to spend time price matching doordash/grubhub on orders - so whoever has the bigger network/more customers will get the most folks.