No, camo isn't necessary
But I'm so old, I can remember when camo wasn't generally worn by the military.
If you're young, how do you really avoid camo.
And avoid a gps and use a compass; avoid a electronic distance finder and use your eyeballs; sight a rifle with a mechanical electronic device, while some oldtimer is using a big orange vase to sight in.
Some things can still work, but can never be accepted again. By newbies anyways.