Weight training can be super dangerous if you don’t know what you’re doing, you can easily do significant damage to your back or knees doing fairly basic exercises like a deadlift or squat incorrectly.
Especially as weight training is increasingly encouraged for the elderly, personal training seems a fairly reasonable job. Admittedly, like any other job, there are folks who provide little to no value (think of the teachers just waiting to collect their pensions) but that’s not to say it can’t be a super useful industry.
Don’t be ridiculous.
Though, it may have been the 12 foot piranha bees.