Yeah, a dedicated actor can trivially just make meta-posting frameworks and tools for any number of services. It's not as if any of them are magic, at the end of the day it still all boils down to https/POST/GET and such, even if no official API is provided. The exact same message could be posted to as many places as desired for the same amount of effort. Bots will be able to function just as easily. If anything one would expect reduced scale would increase the difficulty of handling a very large scale adversary like a state actor. It would only seem to disadvantage smaller players.
And the article also lumps together wildly divergent companies in the same bucket while ignoring where scale is necessary. If you're talking about Apple for example that necessarily means talking hardware since they're primarily a hardware company, but hardware capex is getting ever higher. What's the plan for getting technologies to market where combined upfront expenditures are in the many billions of dollars? Fabricators and state of the art SOC design aren't getting cheaper. Neither are blue sky but critical next generation technologies like future display improvements (microled, direct retinal projection, or whatever).
I mean, a lot of this can be argued as a failure of government. Ideally there would be way more basic R&D happening there with way less red tape with the results then available for all. Government (at least in a democracy) is the natural place to be doing public service security help, and to handle authentication services when two strangers want to have a trusted identity foundation between them. But in reality government is not doing a great job of any of this, nor does it seem set to do in the near future, but we need it anyway. I don't even think giant scale corps have actually been all bad by any means for things like privacy vis-a-vis government, because while sometimes they can cooperate they can also oppose and be impossible to trivially knock down. Would a bunch of tiny random generi-phone corps really have been more effective then Apple at opposing the FBI for example?
Our system is very, very far from perfect. But it's also got us some frankly amazing and wonderful stuff. I think everybody should be instantly and inherently suspicious of "revolution" type change proposals. There is a real risk of tossing the good with the bad and unintended consequences and even opening the door for something way worse. Incremental, focused changes with clear specific goals in mind and then seeing how they work (auto sunset would be nice to see more) normally seem like the more effective way to go.