If Epic manages to carve a sizable chunk of the market with exclusive deals, why would it ever stop doing what worked so well and start worrying about features and refund policies?
Because Fornite money is not infinite.
They can fund games, guarantee sales because right now they sit on pot of gold.
But that pot of gold will eventually dry up.
It is also problem of scale. Right now they can fund it but when they will get that sizeable chunk of market and games will start selling well there stuff like guaranteed sales etc will be things that will go into 10s and 100s of millions and that is something even Fornite money can't sustain for long period of time.
The other avenue here that is worth mentioning is that this might push other stores to fund themselves some games.
Velve has minimal cost of operating but they take 30% cut for years upon years. If Epic will start to eat into their business they will have to answer themselves.
Remember when GOG got into market ? They were the ones who started this whole free games on their store every once in while. What happened after that ? Both steam and rest started to do it because they realized it is good strategy to get people using their store.
From dev position it will be really fucking great situation. In current situation Steam doesn't give a flying fuck about you as developer. Meanwhile Epic is behaving like pimp who showers you as a dev with money because by doing that they will grow.
So imagine for a second that Steam and maybe 1 or 2 other join that practice. Suddenly as a small dev you go from 0 support to 2-4 places that would give you something for giving your game exclusivity to their store.
And it is not like PC is console market so regardless of what store you choose your game will be played by everyone who wants to play it.
Also people who believe Steam benevolence: Steam never improved because it wanted to give you great service. They improved because their main competitor wasn't on PC but on consoles. They improved tools, network etc because they wanted to get console people. This is the reason why they introduced Big Picture, Steam Link and other stuff. They also competed with themselves because they knew that by improving their services they can increase market size.
So adding Epic or other big stores just gives Steam even more incentive to improve in long run.
Who know maybe if Epic will have ability to stop updates on demand and stay on one version of patch, Steam will go back to their earlier rules. Praise competition !