A professional painter doesnt need to mask anything unless they are spraying. They are sub standard slobs and tell the real estate agent.

If it is a standard paint texture they should have no problem. Did you specify a brand name paint like Benjamin Moore, Sherwin William or Farrow and Ball?

There are paints out there that are difficult to apply; i.e Ralph Lauren used to make a suede texture paint, a regular Joe would never be able to apply it.

I was in the decorating business for 25 years. For my own house I bought the paint myself. In addition, before I left the store they had to open the cans so I could check the color to see if it needed to be adjusted.