Retail pricing engines value your car against what similar cars fetch on a forecourt, and forecourt buyers flinch at six-figure mileage. So the curve drops hard past 100,000 miles and keeps falling, whatever the condition, because the engine is pricing the audience's nerves rather than the machine.
That is a fact about one outlet, not about your car. Mechanically, a high-mileage car that lived on motorways and never missed a service is often healthier than a low-mileage car that spent a decade on cold starts and short hops. The trade prices that reality, which is why a trade offer on a high-miler is usually the number worth having.