Hi
Fair challenge, and for a lot of personal finance tooling it's exactly right — and honestly for double-entry too, in two cases: if your finances are simple (one account, a salary), it's overkill; and if you track meticulously but never act on the picture, it's just theater with better-looking books.
Where it earns its keep is when the single-stream "money in / money out" view starts lying to you — several accounts, some debt, reimbursements, an asset or two — because a spending pie chart can't tell you where you actually stand. Double-entry forces the books to balance, which catches errors and gives you a real net-worth position instead of a vibe
Author here. I'm a certified accountant. I ran my own finances in a double-entry Excel/VBA system for years because the off-the-shelf options forced a choice I didn't like: GnuCash (correct, but heavy enough that even I dreaded the daily entry) or the app-store budgeting apps (pleasant, single-entry, cloud-hosted, usually wanting a bank login).
So I built a local-first double-entry desktop app — a plain local database file on your own machine, no telemetry, no aggregator. Happy to talk about the local-first trade-offs (no auto bank sync is the price), or why I went one-time-purchase instead of subscription. Not here to pitch — genuinely interested in how others in this crowd handle their own books.