I'd be ok with it as long as the delivery platform makes it clear that you can order food but the restaurant isn't a participant in the platform, so the experience may not be optimized.

I was recently lamenting that I haven't had some favorite items from Trader Joe's in a while, because I've been using grocery delivery during the pandemic and TJ's refuses to partner with Instacart or provide their own delivery. I then came across Dumpling, a sort-of Instacart competitor where you connect with an individual who does the shopping/delivery for you, but they aren't limited to "officially supported" stores. I have no problem with this, and neither should Trader Joe's. It's simply an individual buying food from them and dropping it off somewhere.

Overriding the restaurant's contact info is sketchy. The food may not travel well, but some restaurants refuse to do takeout (either entirely or for certain dishes). But the basic act of paying a service to pick up something on your behalf isn't problematic to me. The restaurant shouldn't care if I pick up my order, or my wife picks up my order, or GrubHub picks up my order.