And more non trivial amounts of money on parts, maintenance and inspections. Lots of moving parts. Lots of complexity. Lots of engineering hours spent on keeping it all running smoothly. Electrical planes still need inspections but they are a lot more robust and the complexity of maintaining, inspecting, and operating them is at least an order of magnitude lower. And they break down in less and less expensive ways and probably less often too.
The third expensive component is staffing. Pilots are expensive and for complex aircraft they need lots of training. So, simple electrical airplanes lower the training cost and make it easier to train and find new pilots. And complexity is also a reason you often need two pilots. Smaller/simpler airplanes can be one pilot operations. And of course replacing pilots entirely when these things become autonomous brings further cost savings. The flip side is that lots of small planes require more pilots.
Finally, big airports are expensive. You have to pay landing fees in lots of places. And service fees. And missing your assigned slot because of delays is expensive. That too goes away if you start flying from less busy/cheaper airports.
So, there a few additional savings here beyond fuel. But that is the biggest one.
IMHO this is going to be a repeat of the EV revolution a decade ago. But minus a lot of the emotional bickering about range anxiety, etc. Most planes are operated by for profit businesses. The second something cheap becomes available, they'll be all over it. In the same way using electrical vans vs. ice vans is not a topic of debate in the industry. You get the electrical van if you can. They are cheaper to operate. There's zero uncertainty on that front so you see essentially all large fleets transitioning to electrical vans as soon as they can get it done.
With electrical flight, a lot of this stuff is bottle necked on product development (happening), certification (starting to happen), and volume production (not happening yet). Better batteries increase the demand further. But without volume production, demand is not the issue. Supply is. This is and will be supply constrained for a long time.