Spreadsheets win on familiarity
A spreadsheet is cheap, flexible, and easy to share. For a small owner with a handful of simple records, it can be perfectly rational.
The problem begins when the spreadsheet becomes the only system and no one keeps it current after each invoice.
Timelines win on context
A maintenance timeline can keep every event in order while preserving building, asset, vendor, attached invoice, and next-due context.
That context lets the owner filter by roof, HVAC, fire system, or vendor without rebuilding the story manually.
The real comparison is the report
The spreadsheet usually produces another spreadsheet. The timeline should produce a report a buyer, lender, insurer, broker, or partner can read.
That is the Steward process: not more rows, but a better report.