Agree with both of you @CaptainBeanThief and @CoubousAndTourmalet about it being about trust.
When Bill was tiny I followed all the rules that the newer trainers say - I didn't muck about with his food except to add things to his dish, and always taught a swap, but that was so I could be in the position to approach him and his food, and now I can take stuff from his mouth if I have to - because he trusts me. I regularly now towel him down or take his harness on or off when he has his nose in his bowl, because he's not bothered.
It's all about trust. I think things go wrong (especially if there's kids around) when people snatch things from their dogs and the dogs start thinking that nothing is safe and they have to protect themselves.
If you've built trust it sort of doesn't matter how you've done it. We can get a bit tied in knots about things must be done a certain way, but it's the outcome that's important, and that's about how the dog feels as much as how it behaves.
I am stating this from the lofty position of Bill actually being asleep at my feet for once, looking angelic. However, the little sod got through the dog park fence THREE TIMES today, including jumping over the bit I fixed yesterday 🙄