it's a false dichotomy because there is a spectrum between open and closed networks. he doesn't mention authentication and paid services as a DoS and spam mitigation method. he doesn't mention simple stuff like temporary IP blocks for short term attacks (bitcoin's p2p network has this).
everything except for securing the money with PoW is a futile effort, just look up Bitmessage in the history. it is never going to work because if it becomes valuable to bypass it, there will be ASICs for bypassing it, and regular joes won't be able to crunch smaller message hashes than asics can, we already saw this game play out (and why i wasn't a maxi until the death of PoW in about 2019)
these proof of shit things don't do shit. it's a lot of watts wasted for nothing, because you can just have a permissioned system much simpler, and in the end proof of stake and proof of space/time stuff is ultimately vulnerable to all kinds of attacks, most of them not mathematical. proof of stake is completely vulnerable to determined attackers and they then become the threat in the system (i saw this happen in 2016, the bad guys know very well the power they get by early adoption and using their early adopter power to make the network favor them).
as for WoT failing, bullshit. it hasn't hardly even been used in email at all. it's just too easy to inject yourself into people's networks with all kinds of social attacks. it really doesn't scale beyond dunbars number, and everyone in the village has to be extremely skeptical of everyone. really you shouldn't even bother using it without actually physically meeting and there signing your attestations. but as one measure among a palette of options, it is a good way to build a base of confidence in a user not being malicious.
ultimately the best solutions involve subscription access to data storage and relaying on the network, because you can't game money. which is why the money is also so very important, it's the number one security mechanism, combined with authentication.
unfortunately most of the bobbleheads of nostr don't think that paid subscriptions and auth are good because it "closes up access to newbies" bullshit, because the walled garden app stores are doing perfectly fine with subscriptions and advertising and multiple tiers of privilege.
which is why i strongly agree with the point about this black and white absolutist thinking. nostr as a protocol does not have an opinion about any of these things. thankfully. unlike pubky, which is married to peer to peer network systems, and mastodon and bluesky which are married to pyramid federations, and shit like that ethereum social network, which is now pretty much ded, and always was rubbish, based on the IPFS consensus algorithm which doesn't scale. or the ethereum proof of stake bullshit, which also doesn't scale and is a false image of open, because the top stakers are in control of the consensus rules.