A Fujitsu S1500 ScanSnap, dual-sided, document scanner (now discontinued, replacement might be the iX1600). Completely changed how I manage my personal documents (e.g. financial, invoices, receipts, product manuals, medical info, business docs, recreation and hobby stuff, etc). Anything remotely important, I scan to PDF, which triggers automatic OCR that is reasonably accurate, then I upload the PDF to Google Drive,…
Like you I put the documents in a hierarchy of folders and mix with downloaded "official" PDFs, and I use yyyy-mm-dd in the filenames and folders. But, I must admit, a big part of my filing system is often a pile of physical papers stacked up next to the scanner that I haven't got around to yet... But I'd still recommend it.