If you can live with some manual work and no OCR, the digital version of a filing cabinet is scanning everything as (multi-page) PDFs and naming the files like

If you can live with some manual work and no OCR, the digital version of a filing cabinet is scanning everything as (multi-page) PDFs and naming the files like "2018-07-24 #invoice #ACME #business.pdf". Then you can easily find the right document with just Spotlight or similar. Fully cross platform and likely to be readable by any device now and in the future.