It's best not to think of them as straight up replacements in all cases because there is overlap. Think about drivers and wrenches, do you own battery powered versions? Have they completely replaced your traditional drivers or wrenches? Have they completely replaced your corded power tools? Do you have multiple 12/18/20/24v variants of the same tool?
If someone asked me to mow the lawn at my last home with a battery powered lawn mower, I would have laughed in their face. The roots and rocks in the lawn would have destroyed an electric mower's blade on the first mow. At my current home I would consider it, but yard size might be a limiting factor. For the home I'm in the process of purchasing it will be preferred as the yard is so small..
For really hard woods I get about 30-45 min out of the chain saw per battery. I use it for chopping up fallen trees (I live in a heavily-wooded area) so haven't done firewood exactly. I have 2 batteries and I get tired before I run down the second one.
Its kinda fun how it goes from dead silent to ripping through a tree. Although the bar length is probably too short for your needs. Plus a cord is a lot of wood (to me).
I figured anything that needs a more powerful chainsaw is best left to a professional anyway, so the battery-powered saw acts like a built-in buffer on hurting myself.
One of the things that might not be clear to users of the gas equipment, when you say "30-45 min" that means active cutting. Unlike a 2-stroke, it doesn't have to be burning gas to be ready to cut.
OTOH, there's no fussing, it's quieter, and I also got a brush cutter attachment which can handle some places I pretty much had to do manually before.