The likes of Karen Coffee and her convuluted way of breastfeeding including pumping, bottles and different types of formula
I never tried pumping on any of mine and I was lucky enough that my supply just seemed regular so I could just whip the boob out if I was out and about or middle of the night etc. The handiest thing ever, no bottles to make or sterilise and I got a decent rest at night aswell. I know not everyone is as lucky with under/over supply or having to return to work but I would seriously recommend exclusively boob if you can. I wonder with the early pumping for no apparent reason aswell is that what affects their supply, and it’s a vicious cycle then of having to top up with formula, having to pump etc. There’s nothing wrong with formula either, it just defeats the purpose of the handiness of breastfeeding