the problems with junk in the bottom, especially low beds is leave enough room for root depth, especially for root vegies like carrot. The next is How much they will sink by next year when all the leaves/cardboard decomposes. But thats just the way it goes with raised beds, It seems like you fill them for the first few years every spring. Everything in gardening takes a long time to get close to the goalpost. Tall beds are the same way X3. Your soil might be better, Mine are all topped with peat, compost and perlite. some of my tall beds were used as composter for a year or 2, then topped and planted.