I'd say Waves is absolutely the right platform for this use case. There are many reasons for that, including fast and cheap txs and easy token creation. That's going to be pretty important for HOLDVEST as they create tradeable index funds and burn tokens collected as fees. I can't see that would work on Ethereum very well; it would require a different business model.
But as said above, the blockchain itself barely matters. It's all going to be under the hood in the HOLDVEST platform anyway. What matters is that it works efficiently. You won't need to interact directly with the blockchain in question unless you specifically choose to.