The only downside I see for electric yard equipment is the vendor lock-in with batteries. Other than that, they work just fine.
Pay up front for two batteries and a fast-enough charger, and you can charge one battery while you wear the other down; there's still some downtime, but after wearing out a battery the human operator probably needs some downtime, too.
The cost is basically equivalent, minus the battery cost; consider it a prepayment for gasoline, and it probably works out on that front, too.
There are a few large vendors to choose form though. While you have to choose your battery system up front, there are some good choices. the vendors have to compete as well as for companies they have stuff and batteries break all the time so if one vendor is a problem they just move one crew to a different system and distribute their old stuff to other crews. Or just start buying the new vendor for all crews and when not much of the old stuff is left throw it away.
Note that the above is about professional grade tools where you will find is useful to be locked into a battery system. For typical people have a drill on a different battery from the blower isn't a big deal, just buy a couple batteries. When the battery wears out in 10 years buy a whole new tool with a new battery.
Vendor lock-in on those batteries might not be quite as "lock-y" as other examples of vendor lock-in.
One can buy or print[1] cheap adaptors to use cross-brand batteries.
I wonder if it would be plausible to manufacture/sell a line of generic batteries with easily swappable adaptors for major brands, similar to how some AC/DC adaptors have a replaceable wall socket connection for different countries. Perhaps someone on HN knowledgeable on such things knows if there would be some technical or legal issue with that?
I bought a Dewalt battery -> Ryobi tool converter so I could use their cordless PEX cincher. It works fine. But I left the battery connected for some days (something I do all the time with the Dewalt tools), and it bricked the battery. Presumably it was lacking some sense/control lines, or the adapter had its own large quiescent draw, or maybe that's just the expected behavior for the Ryobi system? Obviously I accept the blame and I won't make that mistake again, but the point is it's not seamless. Also the adapter certainly did affect the weight/balance.
I don't see any hard impediment to making compatible batteries, it just feels like a soft lock in of momentum where it's easiest to go with the flow. I've seen plenty of aftermarket batteries for the major brands, but I don't use up enough batteries where I want to chance them having a very limited lifespan (as Chineseum batteries often do IME). I'd rather pay slightly more for a solid brand and know it will last for several years. And I don't think there are any incentives for the name brands to make batteries that work with each other, especially considering there are only a handful of companies making the major brands.
I've pondered buying more Ryobi tools since I have the means to power them, but then I ask myself if I really need to buy it at all rather than buy lower quality (eg lack of brushless motors). Perhaps that calculus would be different if I had an adapter to Milwaukee and was looking at their tools, but honestly Dewalt has swamped the market with enough different models that the last thing I need is to figure out other company's line (more soft lock in!). And some tools are fine in corded versions from whatever brand, like I'm contemplating a handheld planer and don't see how cordless would be super helpful.
Pay up front for two batteries and a fast-enough charger, and you can charge one battery while you wear the other down; there's still some downtime, but after wearing out a battery the human operator probably needs some downtime, too.
The cost is basically equivalent, minus the battery cost; consider it a prepayment for gasoline, and it probably works out on that front, too.