The market for an EV truck is quite niche and appears to be already saturated. EV truck adoption will take longer simply due to the use cases for a pickup truck (e.g. towing, payload) and the limitations of current battery tech
Maybe the problem isn't the market for an EV truck, but rather for one that only has a range of 300 miles and costs $10K more than the gas equivalent at every trim level. What this really says is that the early adopter market was smaller than they expected and the price + limitations aren't yet palatable for a more general audience.