​Profitability on a junk removal service

living south Jersey and I was thinking of starting a junk removal business. I’m getting a lot of shit from family members talking about how that will never be able to be a full-time income stream and that it is only a side hustle. I live in as a very big population and I don’t think I will find a shortage of work. I don’t really understand why they say it doesn’t full time income capability though. If the work is there, it’s there. Taking into consideration the start up cost, gas, and dumping at a landfill cost, I’m not really sure what else I’m not taking into consideration. For now, I was thinking of just buying an older work fan and using that. Will be doing a lot of door knocking and placing yard signs for advertising until I can get it off the ground

I come from a, go to college, get a job, get a nice pension and retire at 45 kind of family.