Yes, and not everyone can get much milk from a pump. And as others have mentioned, some ebf babies just will not take a bottle. It’s a big expenditure for something you may not be able to use much, so I would see how things go and whether you feel you need one.
My twins couldn’t latch properly after months of nicu and tube feeding so I ended up pumping every 2 hours for nearly 8 months, and I still had to heavily supplement with formula (one needed some formula anyway for medical reasons, but I never produced enough for even one baby, let alone too). Exclusive pumping is really hard if your supply isn’t great and I wouldn’t wish it on anyone!
Yes, no one really mentions the fact that if you’re bfing, you need to pump when they have a bottle - to make sure your supply isn’t affected and to stop your boobs exploding / getting mastitis. This calms down as they get bigger, but certainly for the first 4 months, you’d have to pump any time they feed from a bottle and pumping is a lot less pleasant than bfing for most people so it rarely feels worth it. Oh, and if you pump between feeds in those early months you can end up with a big oversupply which isn’t a good thing.
I think pumps have become a lot more common now because of American maternity leave being so short - so many American women having to pump because they have to go to back to work so soon. I think it’s only in recent years that bfing mums think they need an electric breast pump.
You might want to have a look at the haakaa - it’s a soft silicone “pump” that attaches to your other breast while you’re feeding, and the suction draws some milk out, plus it catches whatever you leak while feeding from the other side. It’s a good way to build up a small freezer stash without having to do much extra work. Most bfing mums I know love it, and it means they have enough for an occasional bottle feed just from breastfeeding without extra pumping sessions.