A backpack is by far the best carry (weight balanced across both shoulders). Some (better for less gear) have side entry, so you shrug one shoulder out of its strap & swing the bag round & under to get at your stuff. With others (better for tons of gear) you have to take the bag off - a bit more laborious & less instant.
What else do you need to carry - clothing, lunch, shopping?
For a camera body & a couple of lenses I like a shoulder bag (with strap round the neck & across the body). For camera body & one lens, I prefer a pouch with shoulder strap - that much neater whilst out & about - when you need greater security or weather-protection it can be stashed inside the general-purpose rucksack that you might have along anyway.
It relates to where you go & how far. If you rarely step more than a couple of metres from your car, it hardly matters at all.