You know I really don't care because if Valve DOESN'T give a damn about this and from the looks of it. They don't. Because they haven't done anything to attack back and it seems like they are sitting on their hands because if they did they would've done something by now. What Epic Games is doing is trying to monopolize the PC gaming market and turn it into a console market where exclusively of this nature occurs and I don't see Valve doing anything to try and counter it.
They counter it by not playing Epic's game and continuing to operate as usual. Give Epic enough rope to hang themselves, etc.
Clearly they care, but having them employ similar tactics in retaliation would be even more disastrous. I'm not sure what you have in mind though? Honestly Valve are doing fine amidst all of this and judging by the high volume of high profile games recently confirmed for steam, they'll continue to be fine.
I'm not even sure Epic have a plan outside of the whole wrangling a captive audience thing anyway. If they have, for example, Shenmue fans (which it really seems that they don't) what do they do to keep them after? What do they do to keep anyone they draw in for an exclusive or free game?
Most of the titles they're snatching like this and Phoenix Point are far from being gigantic draws and even the Ubisoft deal benefits Ubisoft more than Epic. It's hard for me to understand how they want this all to transition once they're done blowing fortnite cash when they don't seem to want to cultivate an audience that likes them, their practices or their platform.
Maybe you can get people on your platform by force, but you gotta get them to stay, and eventually you gotta at least try to make them choose it voluntarily. Gonna be tough at this rate to say the least. Their safest bet is pulling in their built in audience, but again, not sure Phoenix Point and Shenmue are going to blow away the fortnight crowd. It all seems like a total mess and I'd love to know how well it's working for them and the publishers/devs involved.