Canada

There needs to be services that directly connect farmers with consumers.

There are many.

given that many people use another middleman (Instacart, etc.) to actually get their groceries.

I have done some consulting for a business that is trying to be much like Instacart for farm-to-consumer transactions. They have a strong niche customer base of those with a certain conviction, but I don't see it ever being something the masses will use. I think you might be underplaying the service a grocery store does provide.

I have no idea how to reach out to farmers

Well, I'm one. You have my ear.

I'm probably not the kind of farmer you need, though. I want to dump all of my product, which could be enough to feed hundreds of thousands of people or more (and my farm is small!), off at harvest and move on. You need mass distribution to be able to absorb that.

The farmers you find at farmers markets would be a better fit, I imagine. If you are serious about this, go there and talk to them. They're usually friendly and interested in this type of thing. If you can help them better connect with the customer, they will be listening.