Online dating doesn't simply connect you to "new" people. It connects you to them privately. It is a setting in which you and you alone need to judge this person and how suitable they are as a partner for you.
I grew up in the Deep South. * I attended public school. I had non-white classmates. I knew guys who were Black or Hispanic who were interested in me.
But, I had no path forward.
In a racist environment, just talking to someone of color in a flirty way will get significant social push back. You have to be willing and able to stand your ground in order to pursue the relationship at all. People don't want to deal with something like that at the curiosity stage. Its very existence helps kill relationships before they can begin. It is just too much drama and makes it too hard to navigate the relationship.
Online dating lets you talk to people without all that. It lets you say "Hi!" and flirt without deciding five minutes after you met them that standing down the entire world is a thing you are up for.
No one in their right mind is up for that just to have coffee. You commit to that at the marriage stage, not at the making eyes at each other stage. If you have to make that decision before you can even chat them up, 99 percent of the time the decision will be to not chat them up to begin with.
Edit: I will add that the privacy angle is likely a large factor in why online dating has been so popular for starting homosexual relationships.
* A long time ago. Hopefully, it's better now.