Yeah, backgrounds are such a great roleplaying tool. One of my first 5e characters was a barbarian, and, while normally such a character is often roleplayed as a dumb brute (though it wouldn't have made sense with him, since I somehow managed to roll him with all stats at least above a 14, with a couple of 18's), the fact that he was a guild merchant played a much bigger role in how he interacted with people than his barbarianism (which I decided was something of a family tradition, which he would tap into when things got violent.)
Another great one was my half-elf noble warlock. Technically he was heir to the throne, but he had enough political enemies due to his parentage (the other half was half-orc, in a union meant to bring peace with the nearby half-orc kingdom, though his half-orc mother was eventually assassinated) that he didn't dare stick around the elven kingdom, and instead sought the help of a mysterious Archfey patron to give him the power to take on his enemies. And, in play, it was fun to be a haughty noble who didn't understand that not everyone cares about his noble status (especially a bunch of dwarves who never really leave their mountain nation and don't really care much about the outside world except in regards to trade).
And the current character I'm playing is a bard with the pirate background, so pretty much all his spells have a pirate theme, like I use Find Familiar to have parrot familiar, and I can use Bestow Curse, which I fluff as giving them a black spot, and I keep my stuff in a Leomund's Secret Chest.
Also, my backup character I'm planning is a conjuration-specialist wizard, and I'm planning that he used to be a charlatan who specialized in shell games, and he's going to have been trained by a PC from a previous game who was an evocation-specialist wizard who I believe had the criminal background or somesuch and used to make money fencing magical goods.
So, yeah, I think backgrounds help you get a lot more character out of your characters, even if they don't have that much mechanical weight.