After the first 6 or 7 months having 2 was easier than having one - it depends on both personality and age gaps I think. I have a barely 2 year age gap from 1-2 and fairly soon they could do things together. I'd been a childminder pre dc2 so dc1 was never a full time only, and I sah aside from teaching evening classes (and later a 1 day per week job in a school) after they were in bed and treated parenting as childminding until dc2 was 3. It was brilliant. Such a fantastic 3 years.
I found it about a million times harder, totally unexpectedly, having dc3 as the older 2 had moved on and it was like having 2 + an entirely seperate only until dc3 was about 4.
Dc1 and 2 were devoted to one another and interested in similar activities, stories, activities etc and in a similar schedule - it was so hard slotting dc3 in.
However once dc1 was 9 or 10 and dc2 7 or 8, dc1 "outgrew" dc2 to an extent and wanted to spend more time with her friends, so dc2 turned to dc3 and now they're inseparable and dc1 far more grown up (dc1 is a teen now).
Small age gaps work better IMO - or rather they pay off quicker.
However it totally depends on personality - I have a sister 2 years younger who's entire reason for being appeared to be to torment me and who believed I'd been put on earth to entertain her - we played together as small children but my parents wouldn't let me stop and insisted that I always be available to play with her and put down my book, go out in my bike with her, do whatever she wanted, say it didn't matter when she destroyed my belongings ou[ of spite, allow her to sleep in my room too and tag along all the time if I had a friend over, because she was small and I should understand and be kind... That kind of sibling relationship where a sibling is pushed to keep a sibling out of parents' hair is shitty.
Be careful about why you have a child as others say. Having another child to entertain your first, or expecting your first to do most of the work keeping your second happy, is absolutely terrible parenting. You have to actually want each individual child separately!