The reason for this is often to make the house more modern, but it can also be simply because these rooms, especially wet areas, require some attention.
Looking around the installed cabinetry in a laundry area can often expose how professional or otherwise DIY the updated area is.
Any areas behind cabinetry where the wall skirting tiling has been removed to enable the fitment of the cabinetry are signs of issues.
If these areas are to be adequately waterproofed, gaps in the tiling should be adequately sealed up at a minimum.
Often the bottom edges of the wall sheeting are exposed, and on occasion, timber wall framing is visible.
Any area, such as under sinks or next to a washing machine, is going to at some point have water leaking issues, and the adjacent room can be affected.
When tiles have been painted over in an effort to update the look without spending a lot of money, indications of shoddy workmanship are frequently visible.
There are businesses that can perform this service for a fair price, and their finished work is frequently excellent, but the process involves many stages.
Prior to applying a mold-killing solution to the grout, the tiles should be cleaned with sugar soap.
After that, the existing tile surface is sanded to make it easier for the new paint to adhere to it. A primer coat and two coats of the actual floor coatings are applied next.
The business doing this work will provide a warranty, and this is the difference between a DIY job and a renovation that will last.
Looking for obvious faults, such as paint runs, suggests it is DIY. I doubt that any of the required processes have been completed to ensure the longevity of the paint finish where it has been applied.