I feel like that niche is primarily occupied by the GoPro as most people who put cameras in such extreme situations seem to enjoy posting videos over photos. For anything more than that you might as well get a dive case - the Tough’s water depth rating isn’t that deep and you can get a dive case for an iPhone that will give you 2-3x the depth.
They aren't diveproof though. Even the entry level PADI Open Water qualification allows you to dive deeper than the Tough series is capable of. Past the 15m mark you need a housing, at which point you would be better off with an SLR in a housing.
The Olympus Tough series may be the last man standing in that category until Apple makes a shatterproof and diveproof iPhone.