Nobody wants it and the few that want it don't want to pay for it. Control engineering really isn't a branch of CS, its culturally its own thing.

Also, liability is a never ending hole with the actual PLC. If your web3 capable PLC keeps even 100-500K/Hr of production from running, then people will probably legally come after you.

I've though several time about building a PLC ecosystem taking the best of modern systems. Building up new features to allow the actual equipment manufacturers (OEMs are under-served) to rapidly spin up and manage variants. And enough ecosystem security that at least your production systems won't be ransomwared. But unless there is a wealth person or huge company out there that just absolutely wants to fund it, it's not economically viable (If you are that company or person, contact me).

The dealer networks and middlemen gatekeep the market pretty severely. You would have to essentially hand hold engineers into using it. And you are going to have a hard time selling it to risk-adverse C and D level managers.