They are. The fire department I volunteer at has put the dewalt battery powered chainsaw in service on our engines (which is significant as we deal with a lot of downed trees, etc.)
I am personally (slowly) switching to battery operated tools for lighter duty mowing and trimming at my ranch (dewalt and bosch).
Further, I see that while the big brands (Polaris, Kawasaki, Yamaha) do not yet have electric quads, you can find them on alibaba, etc., to be shipped to the US.
Heavier duty use-cased - like very large chainsaws and mowers - will still have people like me using IC engines but regular homeowners and even contractors/pros will be switched over to battery for almost everything landscaping/mowing related in the next ten years. It couldn't happen too soon.
Also, battery powered chainsaws (husqvarna is well regarded for their chainsaws): https://www.husqvarna.com/us/products/chainsaws/536li-xp/966...
battery powered riding lawnmowers (ryobi not well known for ride-on mowers): https://www.homedepot.com/p/Ryobi-38-in-75-Ah-Battery-Electr...
You might as well ask, if batteries are getting cheap, why isn't anybody making cordless drills?
Electric chainsaws have been a thing for years and have moved from the trimmer size space to the prosumer/light pro space (see the Husqvarna 536Li XP).
Hoover make a full sized appearance canister/upright hybrid vacuum (Air Cordless Lift). In this space, though, I think the prevalence of smaller stick-style cordless vacuums is because the technology enables them rather than because the technology can't be scaled up. The Dyson V6/V7/V8/V10 models aren't great in terms of quality IMO but are very convenient and popular and the V10 is more than sufficient for home vacuuming tasks.
There are riding electric mowers but the cost keeps most off of them and honestly unless it has thermal management I am not soaking money into one.
If anything shows how far they need to go is motorcycles. Yeah there are a few decent ones out there but if you do highway speeds their mileage plummets.
and finally comes charging, it is silly enough with phone, table, head sets, and more. now I will need a garage full of at minimum 20a 240v plugs if not higher rated. homes just are not designed around that yet
The main unknown for me is how durable the tools will be over time, and how the batteries will hold up.