There actually is, and its called Mimblewimble. The original design, without any cryptographic scripting whatsoever, is limited only by the speed of light across the distance between the spatially farthest nodes in the network. It requires no block size, because the only thing that must be preserved is the UTXO set. With its cryptographic scripting capabilities, as all implementations that I know of have now, there is a small piece of data per transaction that must be preserved in perpetuity, and this adds the issues we see with all other blockchains, although orders of magnitude less pronounced.