I think the “on the ground” answer varies depending on you, where you are and what insects are around. 70% of deer tick bites may carry Lyme, but the percentage of insect bites with red rings that are Lyme is probably different. If you’re walking through northeast pine forest or low density suburban woods, assume Lyme!
Red rings from bites are not uncommon in general. I know I get a reaction from horse flies that looks to professionals like a potential deer tick bite with Lyme.
Those of us who just went through the "Brood X" cicada emergence are now going through a glut of something called "oak mites", which apparently feed on the cicada eggs, but also just get everywhere. They are kind of like chiggers, burrowing under the skin, and are too small to see with the naked eye. The "bites" are particularly itchy and can also cause red splotching that may appear ring-like sometimes. I had a minor freak-out the first time I saw a splotch on my 3-yr-old's back, but it didn't spread and the blotchiness actually went away rather quickly. Luckily, these welts don't seem to last as long as mosquito bites.
Also, a tick-bite splotch doesn't always have to be ring-shaped.
Red rings from bites are not uncommon in general. I know I get a reaction from horse flies that looks to professionals like a potential deer tick bite with Lyme.