Think you probably went into the wrong career if your aim was to earn a lot of money, if wages are similar to the UK.
Even if they somehow got sacked for being lazy or whatever, it doesn’t affect your salary, so I wouldn’t really obsess about it? It obviously takes a lot more training to become a doctor and that’s why they’re paid better. Along with the massive responsibility. I’m sure it’s a stressful job and it could be that those other doctors just don’t like that doctor and so are talking shit about them. You don’t monitor this doctor the whole day (if you do then it sounds like you’re not doing your job very well), so you can’t really say how he spends all his time.
Maybe he’s just coasting now, having done the hard stuff. But he had to do the hard work beforehand to get qualified. But yeah if you wanna be a doctor and think you can do it then make that your aim I guess?
Of course you could earn more money doing another job completely unrelated to healthcare if you trained up and progressed enough.
If you enjoy your job then I wouldn’t worry. If you don’t then try to retrain.