When I was growing up, (all?) laundry detergent /was/ powder in a cardboard box. I recently remembered that as we tried to move to powdered detergent again - and found it really difficult to find locally, and at a reasonable price per load. There are some online retailers (like "Meliora") which offer it (but then you're adding the small-scale shipping into the environmental equation), so we've just been buying it in bulk that way. And it works perfectly well. They ship their refills in a small brown paper bag - not sure if it's recycled, but the overall impact has to be minimal compared to plastic tubs.

Same with dishwasher detergent. It /used/ to be powder. There's still powder now easy to find, at least, and it works perfectly fine.

Those pods are the dumbest invention that consumers have fallen for. Pouring powder from the box works much better for cleaning because you want some washing soda in the pre-wash as well as the main wash. Pour some in the compartment that closes and some on the door, or the little compartment that automatically leaks onto the door. Dishwashing pods are a total scam and they clean dishes less well than pouring powder for 8x the cost and a worse environmental impact.

A French company (https://900.care) does that.

No affiliation, but I want to try them out after they popped up in my youtube ads following searches on exactly these kind of products. I do not know if they are good but zt least they tick the sustainability part I was looking for.

You can definitely buy powder in paper/cardboard packaging, at least here in Austria. But I just checked my box, and it's unfortunately not made from recycled fibers. At least recycling this won't be a problem.