I'm in the market for a truck too, and I'd prefer it to be eco-friendly. But sadly I don't think I'll be purchasing an EV because I prefer to buy a couple of years used and I project my Subaru dying on me in the next couple years. So I don't think I'll see any Rivian competitors for sale on the used car market anytime soon.
I'd add that Ford is working on EV and Hybrid options for their F-series. My money is on them or Tesla for delivering the first quality truck worth buying. I think all the other startups will be crushed, as there aren't too many Elon Musk's in charge that can pull a company through many bankruptcy threats and prevail.
Building a quality truck with a solid drive train and suspension is a whole new product, and I'd imagine that is a daunting task for an EV company producing sedans and SUVs (Tesla), and nearly impossible for startups. There are many innovations on trucks that EV manufacturers would have to develop, like the all aluminum body. AFAIK current Tesla bodies are a blend of aluminum and steel. I'm really curious to see how all of this plays out.