A few things.

1. On mine there's a little guard around the sprayer and it peeks down under it when in use. There's also a cleaning mode.
2. I do use a some toilet paper to dry. Less than I would if I wiped. One day I'll upgrade to one of the fancy units with a dryer.
3. I don't know about other people but I move around a bit to make sure that the spray gets everything, including "in there a bit". If you dab to dry and your tp has anything other than water on it you didn't do a good enough job spraying.

It depends on your bowel movements and how much fiber you eat. I still have to wipe a little after the water, but far less than without. Others, drying is enough.

After using one for a while now, it seems so uncivilized not using one now.

Most people do, but a couple squares to pat dry is probably less than you'd use otherwise. Some fancier models have blow dryers. Personally, I won't lie, I'm probably going to sit on the toilet for a few minutes scrolling through Lemmy on my phone after I've done my business so I tend to just air/drip dry.

I have some pretty basic models, and they do a pretty good job getting everything clean, they have a pretty powerful jet. Definitely a lot better than I've ever been able to do with TP.

Okay but are you just using toilet paper to dry afterwards?

Some have built in dyers. Even with it, sometimes it feels a small dab helps some more, but it's not really necessary. Also, that water should be clean at that point... Do you perfectly dry your ass with a towel after showering? Etc

And does just water actually get it all?

Usually. You can also run them more than once. Some have "pressure" settings. Some move back and forth. And you can always check with paper, and see if you need to change something or run another cycle.

You've still got to get in there a bit right?

I've never had to. Occasionally run a second cycle, but no.

You do dry with toilet paper. Personally if the toilet paper doesn't come up clean I go back with the water again until it does.

Of course you use tp afterwards, your ass is now soaking wet. Wipe, rinse, then wipe again.

My dude, your ball hair lives inches away from your butthole, maybe not even that far depending on how saggy your balls are, how long your hairs are, and how supportive your underwear is. I promise you that nothing that's splashing onto your balls is any worse than what's already there.

It’s not that powerful of a jet of water. I mean, I’m sure there is some, but if you’re doing it right, only the parts you want to get wet are getting wet. Besides, the alternative is like using a paper towel to clean peanut butter from a shag carpet.

Mine has a nozzle adjust so that you can do either front to back or just back.

There's a lot of options out there, I've seen some really fancy ones with a lot of bells and whistles, but my personal experience is that most of the ones I see people buying and installing are pretty basic mechanical devices hooked up to a water line with no electrical components. Just pieces of plastic and/or metal being acted upon by other pieces of plastic/metal and water pressure.

Most people are retrofitting them into existing bathrooms, often they don't have convenient electrical lines/outlets close enough to their toilet for a clean-looking install and don't care enough to run them, and needing to recharge or replace batteries in their toilet isn't something they're particularly interested in doing (I fall into this category myself)

Personally I have 3 toilets with 3 bidets, all basic cold water models with no other features. None of them have convenient power, I'd have to run a cord to the outlet by the sink, or run a new outlet for them. It's certainly doable in all 3 cases, but more work than I care to put into it, and I'm too stubborn and cheap of a DIY homeowner to hire an electrician for something I could do myself. One of them is close enough to the sink that I could run a hot water line to it without too much bother, but that bathroom is pending a renovation so I'm waiting to see how things look when I get into that before I do it (that bathroom is also furthest from the water heater, so you usually have to run the water for a while before it starts coming out hot from the tap, so kind of less than ideal and maybe not worth it)

On that note, cold water bidets are a little unpleasant at first, but you get used to it really quickly, and if you're kind of a fat sweaty guy like me they're actually pretty refreshing once you're used to them.