They hold up, provided the thickness matches the load. The interlocking format has nothing to do with durability. It describes how the tiles connect, not how much abuse they take. A three-quarter-inch tile absorbs heavy barbell drops as well as a glued-down floor of the same thickness.

The reason interlocking gym flooring gets dismissed as light-duty is that the thin, cheap puzzle mats sold for general use get confused with proper rubber. Commercial-grade tiles in the right thickness are a different product entirely, built to take loaded drops day after day.

The real advantage under heavy lifting is serviceability. With interlocking rubber tiles, a single damaged piece lifts out and gets replaced without disturbing the rest of the floor, which a glued roll cannot offer. Match the thickness to the heaviest lift, the same as any floor, and a tiled setup performs at the same level while staying far easier to repair.