Is the outlet type indicative of problematic wiring
You, or your house inspector, would want to investigate if the "modern wiring" makes it all the way to the outlet boxes (in which case a simple replacement will get you grounded 3-prong outlets) or if it stops short and leaves you with old ungrounded wire to the actual outlets (in which case you'll want to lower your offer by several thousand dollars to pay for the rewiring.)

The triple outlets could just be a fashion choice, but you need to know to make a reasonable offer on the house.