I played it for about 70 hours like 8 months ago, and quite enjoyed it. Will definitely go back, at some point, to see what's been improved. There's a REALLY solid foundation there, I think. I like to say it's the factorio/automation genre, but distilled down to nothing but the gameplay, in its purest, most-concentrated form. My wife and son picked it back up immediately today, when they realized the big update dropped.

One thing they've talked about doing is improving the high-level progression. Specifically, they said their concept for better progression will be that milestone products will feed into future milestones, rather than having them just get thrown away, just like you describe. Not sure if that's made it into the game yet, or not.

For $25 in Early Access, I think it's a deal. If you're really worried about there being enough gameplay/progression to keep you interested, wishlist it, and keep an eye on what the updates are adding.