The is NOT true, the diploma in building course has been around for many decades and graduates have been doing well in life. A lot of them end up as big time contractors. Fresh graduates usually do not have much problem getting employed as they are in demand by employers in the building line.
QS ing is a specialised area of building dealing with costs, estimation, tendering, building accounts, is also a good line to be in. QS are required in almost all building projects and many work for contractors.

Going through a 2-year course in KTAR would give your a good headstart in getting a job.

Somebody who has completed SPM cannot be classified as one 'without education'. The question is whether it is adequate for entry into the job market.

It is true that you can be successful even without tertiary education but the odds are stacked high against you.

Acquiring some vocational skill is a good idea, it will make you more employable. In advanced countries, skilled workers like plumbers, electricians, are in greater demand and earn more than degree holders.

Bear in mind that, once you stop, it would be very hard to pick up studies again at a later stage in life. Persevere for another 2-3 years to pursue a course of your interest and your efforts will be well worth it.