If you look into it you will find that you can buy many indie games directly from the developer and still get a Steam key. If you don't want that Valve charges

If you look into it you will find that you can buy many indie games directly from the developer and still get a Steam key. If you don't want that Valve charges "too much" from indies, then you should be proactive and join other marketplaces. It's a hen-egg situation.