Been discussed many times but to be blunt the Automotive field has become drastically more complex since the 60s, 70s. and 80s however the industry standards for employee selection and training have remained pretty much identical. You haven't been able to fix a car with just a set of wrenches, sockets, and a test light in decades but since tool bills are on the mechanic the shops can ignore that. Unions are also few and far between hence flat rate pay is an industry standard and some (not all) ridiculous book times.
Some, if not most, will say its a terrible field to get into. Some will say they're making great money and are doing fine. Fact of the matter is a auto mechanic or "tech" is still essentially treated as an unskilled profession so the pay is often garbage. Average salary of a mechanic in the US is a pathetic 40k or less while on the flip side, to be truly competent, it requires tens of thousands in tools, a huge wealth of knowledge, a strong body and mind, and continuous training. I struggle to think of a worse field for requiring so much and getting so little in return. You can offset this by getting into good gigs like government fleet or private (that pay well and have good benefits), beating flat rate with tricks and unsavory methods, or becoming specialized in drivability/electrical which is extremely important as vehicles become more and more of a giant computer. The more you know the more you're worth but even then you may have to travel a good bit to find good money. Road techs, heavy equipment, oil and gas, marine etc.. in general all pay better so if you just like playing with and fixing mechanical stuff don't limit yourself to just the automotive field.
If you think you're going to make great money doing brakes, exhaust, suspension and the occasional transmission/engine swap think again. As hard as you might work you're too redundant and employers will abuse that fact and pay you poorly.
Other trades like HVAC, plumbers, electricians, have a similar crappy journeyman program but once that's done your pay can skyrocket (area dependent), and you know your paycheck will be reasonably steady so less worry about paying bills. A shop on flat rate can be a bit like a roller coaster at times.
I'd tell anyone who is thinking about becoming a mechanic to stay in school. Finish high school/get your GED, find a local community college with automotive classes and take them along with others such as business/accounting (to name something common, but there are many choices). This will get you credits and give you an out if you get burned out in your first few years as a mechanic or change your mind. A lot of young guys enjoy doing drive-way repairs and think the field is for them but quickly realize its no fun doing it 5-6 days a week. Whatever you do, do not waste your education funds on a pricey technical college. The vast majority teach you very little and send you on your way AND your "education" is worthless for anything other than a highlight on an automotive resume.
However, there were no benefits like sick leave so, I tried a city fleet gig which had weird hours but, a great working environment with benefits. My fleet gig is the exception. Life at a flat rate dealership can be feast or famine in flat rate land. You can be the best tech in the world but, if customers don't bring their cars in or don't want to spend money on their car, income prospects aren't so good.