data
Just a data point.
I have applied epoxy coating to a workshop floor and a small hangar.
The workshop was basically brand new concrete, no stains, and sufficiently cured per the epoxy instructions. The prep was done with acid etching. The epoxy paint was available at the big box store. It went down fine but after a year of light use, it is peeling in places of foot traffic, and especially where there is contact with the rubber tires of the lawn tractor. All prep was consistent with the product instructions.
The small hangar was prep by scarifying the surface. The prep was completed per product instructions, and the two part "commercial" grade paint was applied. It looked fantastic for about a year; it started peeling where the airplane tires were in contact and near the door.
No judgement or recommendations, just data points.
Two different products, two different preps, same basic result.
I think if I did it again, I would bite the bullet and pay a professional company to install it and get a warranty...either that or just go with polished concrete...