My 19 month son still has one bottle of formula a day (long story, have tried to switch many times and not successful).
I still sterilise the bottle, because I read formula milk can harbour more bacteria. It's quick and easy so I don't consider it a faff. I also have a 5 month old daughter, and probably on autopilot, when I sterilise her dummies I also sometimes sterilise my sons. Ive never actually thought about it.
My sister however has told me microwaving plastic is dreadful for leaching chemicals and microplastics. I know there's no need to sterilise after 1 year old, it's more a habit I've never questioned.
I'm just wondering does anyone else microwave/sterilise their baby products beyond a year? Is it really that harmful? I suppose I'm trying to ease the mom guilt, although what i probably need is a good nap.