Subaru is not a large car manufacturer. Toyota sells over 10x the amount of cars and Nissan sells 3x-5x, they are not equals. And Nissan did build an electric car 16 years ago and the company is currently circling the drain.
EV development also gets easier every year as it becomes more common. Companies don't have to have cutting-edge technology to compete, and Subaru has plans to release their own EV platform in 2029. I do not expect it to be cutting edge, but loyal Subaru owners won't be expecting that either.
And their US market just happens to overlap with the EV early adopter market. Symmetrical all-wheel drive, the thing that snow drivers need, is easy peasy for an electric.
For context, i had a 2014 BMW i3 for about 8 years, the design was neat, the engineering undependable, an Audi A5 for 2.x years, truly excellent and i loved it like my old used SAAB 900 turbo of long ago, and a BMW i4 xdrive40 for 3 years, truly shitty engineering, but pretty shape and paint job.
The Subaru EV does share components with Toyota/Lexus(/Subaru) but handles __way__ better than the BMW for 2/3 the price, has vastly nicer EV component design (like heat pump and periphery, which is outsourced by BMW and failed on both my i3 and i4).