Traffic and accidents might push you into different routes, especially if you have major decision points like which route you take around some geographic feature. When I drive in Los Angeles decades back even people who’d been driving there for ages wanted traffic reports to pick between roughly equivalent freeways because almost inevitably one of them would have much worse congestion due to an accident and you could save 20+ minutes.

Driving in the London suburbs, I know how to get most places I want to go. In fact I usually know several different routes that are roughly similar in travel time. Google maps is excellent for telling me which one of those routes is least congested right now. So I'm not really using it for navigation, but for congestion information. It very rarely suggests a route I don't know, but I use it all the time anyway.

Although the route is (more or less) fixed and static, the amount of traffic isn't, so it could be useful to be re-routed to avoid congestion.

You’ve clearly not enjoyed the benefits of progress yet where you are. Don’t worry, I’m sure it will reach you eventually. It is progress after all.

If you use the reporting interface they seem to update promptly. There’s a major road near us where Google used to tell people to make a illegal left turn across 4 lanes of traffic, which was common enough that I used to see it almost every time I went by for years. Once I found the well-hidden reporting UI, that stopped two weeks later.

I believe it does when you set your home and work addresses

The Tesla maps do it too, when you tap on the navigation address entry there's a list of 'Suggested' which is learned based on time of day / day of week.

Strange, I have this feature in mine.