Used to work for a large airline IT provider on departure-control software (check-in, boarding, etc.) Each airline on-boarded would demand mandatory features t

Used to work for a large airline IT provider on departure-control software (check-in, boarding, etc.) Each airline on-boarded would demand mandatory features that they couldn't do without. Keep in mind these features weren't free, they were billed market-rate development charges - though the company didn't make money off that, the core business model was usage-based billing. More than 80% of implemented features would go completely unused.