What is the benefit of IOTA over Proof-of-Stake, Proof-of-Storage or a Ripple/Stellar consensus approach?

I get that Proof of Work has scalability issues. But all talk I’ve seen on IOTA seems to assume that all block chain solutions rely on Proof-of-Work. Ripple and Stellar e.g. achieve high transaction throughput on level with VISA. 50k transactions per second.

Neo can do about 1k TPS using PoS. The whole IOTA concept sounds really cool, but I fail to see WHY we need it, when we got simpler allready working solutions, to the problem of low transaction throughput.