Unless the oak tree is far from an electric outlet, even inexpensive plug-in electric chainsaws are much easier to use than gas chainsaws. The high torque means it won't stall out when all but the burliest gas chainsaws give up.
Going to a customer's house and consuming their electric all day isn't going to work out, or having extension cords strung everywhere, where you're literally dropping heavy trees with sharp right angle cuts, and cord snagging brush and branches, and you know, the chainsaw itself which will go through a cord in an instant and if it doesn't you won't be worried about loud noises anymore. Cord powered saws for real crews are not practical at all. That leaves the options - battery powered, and those do not have enough power to cut down large trees (I'm talking about more than falling a tree), or bring your own electric, ie, run a generator, which would be gas powered and just as loud and non-green as gas powered saws and still has the whole cord issue.
Maybe that was the case 5-10 years ago but not these days. A buddy and I cut 10-12" dia tree sections into rounds in short order with a 16" bar Ego chainsaw. It was, let's say, 10% slower than an equivalent Stihl but it had more than enough grunt and was incredibly quiet - no need for ear protection.
If you're using a dinky little 18V chainsaw then they'll choke on anything but the new stuff using 56+ volt batteries pack some serious punch. Gas chainsaws are still needed for some use cases but the lack of noise, exhaust, vibration, and fuel/filter maintenance positions them to fully replace gas chainsaws in the reasonably near future.
That sounds more like a dull chain than a saw issue.