Riot hasnt had a single original idea ever, but at least they know how to keep a game running and how to market it.
When Valves does something it usually changes the industry, may it be Steam, VR, Steam Deck, a new standard for VR Games (Alyx) or now sub tick servers. The issue with Valve is tho that in order to achieve that they are pretty fucking strange in how they handle their projects. They literally talk about ticks and smoke grenades instead of making a "bad ass" trailer like everybody else would do.