I agree that besides Fallout and Elder Scrolls it's not that big of a loss for Sony if you only look at it from a short term market perspective. The thing is though, on a personal Level i cared about a lot of Bethesdas Games and longterm it is important for Publishers to invest in Games that maybe don't make billions of Dollars but are very appealing to certain niches etc. Immersive Sims is a Genre that will probably no longer be availible on Playstation because Arkane was the last studio that made those kind of Games. FPS Games like Doom with Health and Armour pick ups is a thing you will no longer be able to buy on Playstation if no one else does this. Bethesda published a lot of great Games this Gen, maybe they weren't the biggest hits but they had really loyal fanbases.
Sony themselves always invests in those niche Games otherwise The Last Guardian would have never seen the light of day. They are doing a lot less of that now, but with Bethesda gone they also lost a lot of Genres and style of Game that if for example EA would have been bought would not have been lost in comparison. So this actually might hurt the Platform in the long run a lot more. We won't see this in their financials for the next 2 or 3 years but beyond that it could create some sort of damage imo.
The saddest thing for me is Microsoft might still release Elder Scrolls and Fallout on PS because those are the big sellers and cost the most to produce but i don't care about those Games at all.
I share the sentiment. After all, there's a reason why Sony was rumored to be after a similar acquisition: Zenimax was a relevant publisher with lots of talented artirts.
What's transpired here doesn't affect me much personally because I tend to buy few software and always gravitate to the kind of experience that's only available on PS (not out of allegiance, but because it's the tone and style of adventure that I'm able to enjoy after so many years playing). I'll miss Arkane, an studio I thought it was a good fit for PlayStation series a few times, as I'll miss MachineGames and its combination of narrative and fast action. Said that, it won't change in any drastic way how I consume video games (though I understand it'll do for others who enjoyed those IPs more than I did).
In the future, I can only hope they'll anticipate and adjust. I don't expect big acquisitions like many here; I'm not sure if I want them either. I think it's time for new IPs from the already existing PlayStation studios, not outbidding the company that can't be beaten with money. Now there's a hole in the FPS genre, so let's see one of their studios do an FPS; there's a hole as you say with immersive sims (until Deus Ex or Ken Levine come back from wherever they are), let's put someone to work there; if a studio is needed for that purpose, buy one, but do it smartly, at a fair price, because you're David fighting against Goliath, and there's no point in trying to reenact the tale here, it's never going to work. That's what I hope for; who knows what they'll do? I'm sure releasing on PC some big hitters would be far less troubling than exploring all these venues.