Like tor, PoW, and many other decentralized systems, the power inherent in the network is a formula of the number of users of the network that support the infrastructure. In the case of coinjoining (basically tumbling with a bunch of people in a cryptographically safe way), it is hard to move even a couple btc's through Wasabi Wallet (the only working new coinjoin scheme implementation AFAIK) could really use some liquidity. Just google Wasabi Wallet and either get it off github and build it or download it from the website. heres the link but double check https://wasabiwallet.io
Slightly related: What happened to blockchain.info's coinjoin implementation back in the old days? was it not actually doing anything?