Removing rusted galvanized raised beds, what to replace with?

Our new home came with brand new galvanized steel raised beds. In the whirlwind of renovations and moving we figured we would run with it and the first year went fine. The second year they began showing rust, the third year they are all rusted on the inside, and the produce of those beds was really not great. It is hard to tell how not great it was because it was a really not great year in general, with all the wildfire smoke, but I'm inclined to dump all the soil in the woods, recycle the steel, and start over. What should I replace with?

I have access to a lot of woodchips. The paths are all in woodchips. I have tried BTE gardening and I'm doing something wrong, because there is no compost happening down there, just 12-18" of chips over mineral soil. We have lots of earthworms but they inhabit the beds and borders, and have not been transforming the chips. The oldest chip bed is almost 3yo. I grow plants in it by putting compost into the potting holes and pouring on gallons of compost tea and fish sauce. So basically, I would like to use something that isn't more chips.

I could try bed-shaped mini hugels, but the dirt would wash down the sides. There are zero rocks on the land, so a nice rock border is out. I could build a nice border with logs. We have tons of fir, cedar, alder, and pine that are about the right width to stack for a low border, but I worry about ants. This is probably what I'll end up doing, though. We have almost perfected our toad habitat and they do a great job with the ants and the slugs.

Any other ideas? There are going to be 8 un-beds with un-garden soil in them, about 3' by 8'.

Scaffold boards are worth a look, thick enough to last years without treatment and you can usually find them cheap secondhand. My concern with galvanised in beds has always been the zinc leaching anyway, so going untreated timber at least takes that worry off the table.