This story relates to Google Domains, the registrar entity of Google, not the registry entity.

I would personally never trust Google as a registrar because they have a horrible track record regarding customer support. As a gTLD registry though, they’re supervised by the ICANN and just cannot afford to make a shitty job there. Being a registry is also, IMHO, way easier than being a registrar, you obey ICANN rules, but you’re the one setting the rules for the registrars. Google as a registry is fine. You’re free to not trust them either as a registry, but that would be for personal convictions, not objective.

Could you maybe expand on what the risks are with registries?

When I trust a company to be my gTLD registry, what am I trusting them with? Why is Google safer than e.g. the government of Tuvalu, or some private "speculator", if they all have to follow ICANN rules?

ccTLD (2 characters, are usually managed by countries, except for .eu and maybe a handful of other exceptions) *do not* follow ICANN’s rules. Governments are owners of the TLD of their own country, and set the administrative rules. On the admin side, you’re trusting the countries to not change the rules against you. It’s probably not a good idea to rent a .ru if you’re Ukrainian for example. You’re also trusting them regarding a part of the DNS resolution: a DNS query first goes by the root DNS, which will resolve the TLD to the registry’s DNS server, which will resolve the domain to the registrar’s DNS servers, which will do the rest. The registry could theoretically override your records on their layers. So same thing, don’t use a ccTLD you don’t trust (that’s true of all TLDs, but even more for ccTLDs). On a technical side, some countries have crappy infrastructures, so resolution is at risk. It happened to Notion a few months ago with their .so domain (Somalia). Some poor countries delegate the technical side of operations to more reliable registries.

Google is safer because it only manages gTLDs. They can set part of the rules, but not all the rules. They have to follow ICANN’s rules. In particular, the dispute process goes through the ICANN which gives a somewhat neutral safety net. It’s far from perfectly, probably not even good enough, but still gives you more warranties than using a random ccTLD.

Speculators bought newGTLDs in the hope of selling tons of them but often dramatically failed. Registering a gTLD to the ICANN costs at least $400,000 if I remember well, so a lot of crappy newGTLDs are not profitable. When the registry goes bankrupt, I don’t know what happens to the customers. My guess is the ICANN tried to re-sell the TLD management on auction, and if they fail, then people would lose their domain. Very few newGTLDs succeeded, I’d stick with these and not try anything fun but too exotic.

ccTLDs do not have to follow ICANN rules. They are treated as sovereign territory of the country they belong to. On a ccTLD the registry can take your domain from you at any moment for any reason.

While on a com, net, org the US government can take your domain from you at any moment for any reason?

Don't see much of a difference there.

That's not the case. The ICANN is an entity independent from the US. Well, that's not entirely true, but true enough that the US can't just take a .com from someone just like that.

Frankly, I would prefer if the USA just used .us (and .com.us, .org.us, .gov.us, etc) as a ccTDL and left .com, .net, .org, etc to be under the supervision of the UN.

The registry can still cancel registrations. The daily stormer is infamous for being kicked off of every major registry.

Note that .com is a TLD operated by Verisign, not Google, and anyway what is at issue here is the domain registrar, not the domain registry.