I'm not convinced RenVM is really in the middle in its current state. Currently the core team holds all of the keys for the over $300M in Bitcoin stored by their project [0]. I'd take wbtc, which is held by a consortium of well known custodians in the space over that any day.
[0] https://www.theblockcrypto.com/daily/76787/ren-bitcoin-walle...
https://renproject.io
https://mainnet.renproject.io