If you are lucky, as a presenter, a film star, etc, you get a good long run and can wrack up a fantastic money. However, only a few of the presenters (particularly women) get lifetime's career out of what they are doing. Furthermore, if you get accused of something, even if you are cleared, you find you are no longer chosen to present anything. You only have to look at the previously very popular John Leslie to see how your career can be scuppered by unproved allegations.
These days, presenters have to have thick skins to put with the Social Media bullying, the scrutiny of their private lives, etc. It seems like a lot of money but I wonder how many of us could live like they do in a goldfish bowl. The flak a "private" star gets is almost hysterical.
The BBC have to compete with other tv companies and need to attract the talent especially in a day and age where the newer generations don't actually watch live streamed tv but tend to watch Netflix or the like. How on earth do we expect the BBC to maintain high standards, decreasing viewing numbers, no advertising income and free tv licences and still be a going concern. Just like the NHS, we expect far more than they can realistically achieve and many elderly people can easily afford to pay their tv licence.