Somewhat. Depends on what you want to do. Three year ROI can be reasonable. I probably spend about $100-150 per year on garden (and mushroom) stuff, with the higher years being in the beginning or for one time improvements (plus random new seeds to try just for fun). I get about $400-500 worth of produce every year. I try to focus on stuff that limits labor time like weed barrier and raspberries (no weeding, easy to survive, perennial). I also try to focus on expensive stuff like peppers, berries, mushrooms, and hops (for homebrew beer).
I also have an LLC for honey. It's generally low labor (compared to other livestock), but tends to have expensive equipment and replacement costs. It's possible to break even in 3 years on a small scale with cheap equipment.
So it can be productive and a net positive. During the season we can get 50-75% of our fruit and veggies from the garden with the remaining percentage being the desire for varieties I don't grow or can't be grown around here. Plus some canning, freezing, hot sauce, etc for later.. We can also get all the honey we desire, including to make mead, and still make a net profit on the bee operation of $100+ per year (can vary wildly based on the circumstances). I think this is a meaningful amount. Obviously this isn't something that you could scale to turn your 401k into.
Now I do some stuff for fun. This year I'm planning to malt my own wheat and barley that I will grow. Even if grain prices double, that's not going to help me financially since wheat will still be relatively cheap compared to other produce.