I think it's that with vacuum cleaners I have to get them out, deal with the cable, drag the thing around, worry about the cable being too short or long enough or getting stuck around things, mess with the paper bag (I have 3 already, I'm tempted to get a bagless but that'd be yet another vacuum cleaner), if it's a standing cleaner than get frustrated how inflexible and limited in usefulness it is, worry about using it at reasonable hours and for not too long so as not to disturb the neighbours, make sure everything is ready for vacuuming before I vacuum, retrieve that little thing i need it seems to have swallowed, remove that other thing that's clogging its tube, et cetera and et cetera.
What I like about brooms is that I do things at my own time, broom a little, then tidy up a little, broom a little, then pick this little thing up or that. While brooming, I can also listen to some audiobooks, unlike with a noisy vacuum. I can use a big broom, or a tiny one, i can broom standing, or even sitting down. I can broom some area of the room, do something else leaving the broom somewhere as it doesn't take up much space, and the broom itself could even be a little pretty in that simplicity aesthetic so it wouldn't be a sore if left resting on a wall for a little time (unlike a vacuum cleaner - which I must put back in place).
Remarkably I'm finding brooms quite effective. There's nothing easier than just picking up a broom, using it for a few minutes here or there, and putting it back. I feel I could happily broom a few times a day if i need to, no trouble with that, not that I do, but vacuum cleaning feel like such a chore.
I'm particularly fond of two items I bought, made by some Bentley brand, and the reasons are simple; they have great ergonomics, and they're cheap though good looking. One of them is a tiny dustpan and tiny brush/broom. The other is full length standing one. Now here's why I find they have great ergonomics, they're angled and the palm/wrist is facing inwards while sweeping in. I find this makes a great, great difference. I would not want to a a broom where the wrist/palm would be facing downwards in a grip, I hate those, they're a wrist killer.
The more I think about it the more I feel this post is silly, but hey, keeping a clean place is sublime.