I was pretty right-on with our first and really wanted to do cloth nappies but didn't in the end. The up front cost is a LOT, especially given how many people find one brand doesn't work and have to try lots. I could have pissed £300 down the drain very easily. Also, birth to potty is a LIE so you then have to buy MORE cloth nappies in newborn sizes and bigger sizes, or do disposables to start with.
If you've not got a good setup for washing and drying, you end up with nappies hung up all over the place and never a dry one to be found. In our old house, the washing machine was in a concrete outhouse so I had to go out the back door into this spidery hut thing to do a wash. And I had nowhere to dry them indoors when it was raining.
And, to be honest, having a baby was such a total mindfuck that when I couldn't cope, cloth nappies was so totally optional (unlike, say, feeding the baby) that it was the absolute first thing that fell off the list.
We've since done cloth nappies with our second (since 4m, now 1yo) and in a different house with my husband studying from home and not being smacked in the face with the horror of a firstborn, it's been pretty easy. Loads of space to dry them, we change her right by the utility room (we have a utility room!!! indoors!!!). We still do a disposable overnight because sleep is more important than polar bears. We're also home all the time with #2 (cuz lockdown) so very rarely have to lug all the stuff around.
And they are confusing when you start researching. All the different types, all the different brands, everyone saying X was brilliant and they just put a Y booster in and doubled with with a Z cover... You don't know which way is up by the end, and you certainly don't know which to buy!
Honestly, I think the biggest reason is that it's optional and having a baby is hard enough and expensive enough (or at least all the convenience food we bought ourselves was!) that you're not about to do hours of research, spend a lot of money on something that might not work, and give yourself extra compulsory chores unless you're REALLY committed. Other reusable products don't come into your life at the very moment at which you have the least capacity to deal with both thinking something through and physically doing it.
If we had all the money in the world, I might have used a reusable nappy service with both. They do all the work, I can switch kinds of nappy around to try them out/with changing needs without further spending, best of both worlds for me.
What I never found to be true was that disposables means you don't have to deal with wee and poo as much. Either way, you have to scrape poo off a bottom. Cloth nappies are much less smelly when they're hanging around, as most of the poo goes into the loo and a wet bag gets a better seal than a bin bag. Then the washing machine just magics it away.