It's much more difficult (for me).
"Three Shoes, One Sock and No hairbrush" is a good read for those finding it tough with two.
It is lovely and easier when they play together but mentally I have really struggled with the noise, the fighting, bedtimes, being pulled in different directions, them needing different things, shouts of "mummy", "mummy" all day long. The logistics can be tricky. When they are younger a sling and pushchair combo is great.
When they are older one gets tired and won't walk, so the other decides they want to be carried too. You have to find things to do suitable for two children of different ages/stages in their development.
One wants a toy, the other wants the same thing at exactly the same time. Neither wants to go to bed first. Or if you are trying to get one to bed/nap, the other will sabotage it by shouting loudly or jumping up and down while you are trying to read to the other or calm them down. Doing bedtimes on your own is hard. I used to draft in people to help occasionally if DH wasn't around.
Having a baby the second time was a breeze but once that baby started grabbing things off its sister, things got very tricky for a while. Now they are both talking, yelling, it's very difficult to get any mental space in daylight hours. It can be fun and I'm sure it will be fantastic to have two when they are older but when they and I are both at home it is hard.
It's great when the eldest starts school though. Looking after one seems so easy once you have two.