Exactly. Expected returns from investing BTC in Crypto Games are quite low, but unfortunately there aren't that many other options (at least that I know of), so I have a bit there.
Instead of storing our coins in our cold wallet some of those coins can be invested in these trusted sites because even though profits are not that great but still we can earn some money over the time. But remember don't invest all your coins in a single site.
I had invested around 35 LTC in last November and now I got around a few extra LTC profit. LTC prices went down a lot after my investment but that is a different issue.