.com/.net/.org - your name is probably gone

New gTLDs - The registry can pretty much arbitrarily set prices in the future

ccTLDs - Politics might make you have to change domain (e.g. UK owners of .eu)

Pick your poison, I tend to stick with the original TLDs and my own country's ccTLD

Some country tlds are risky because they don't necessarily check residency requirements when you purchase, but might later if your domain catches their attention. Not all have residency requirements, but some do.

There's also some TLDs that are well known for web spam, phishing, or email spam, sometimes because of free or cheap subdomains. Those might have issues getting indexed in Google, or issues with SMTP delivery. Google once deindexed the entirety of *.co.cc, for example.

A couple, but they're all "human" reasons and not really technical. The TLDs records will be served off the gTLD nameservers like everything else, you can change your own nameservers from there, and DNS is slow as hell anyway (by modern standards) so it's already not like it's tightly optimized usually, and performance as perceived by the end user is greatly predicated on how warm their cache is. So any performance difference between nameservers probably barely matters unless you're like Amazon or something.

Anyway, non-objective reasons I can think of:

Lots of people don't know anything but com exists.

Com is definitely still dominant, so someone sitting on yourthing.com when yourthing.biz.no is your real site will probably be getting some chunk of your traffic. Imagine if Amazon.co.uk was the real Amazon and Amazon.com was like, a news website dedicated to posting all the bad stuff Amazon does. Tbh that'd be nice for society but you can probably understand it would be undesirable for a company.

.io is one of the only ones that's managed to kinda read com-like status, and it's only for a niche (though a lucrative niche!) audience.

The $1 TLDs like .top .xyz .fun etc will be blocked in a lot of places due to heavy spam and malware distribution.

I remember reading a blog post that I can't find that one company saw a massive uptick on email deliverability when they stop using .xyz and moved to a more standard one.

It makes some sense, .xyz are so cheap that I've bought mines for $1 so just buying a domain every day isn't outside the realms of possbility for spammers. Personally, I just use my .xyz domains for internal stuff where I still want things connected to the internet and available.

While there are some performance differences [1] between TLDs, I don't personally think it should factor very heavily when choosing one.

As for reliability, there have been a few ".io" outages and I remember ".club" going down a few years ago but DNS makes complete TLD outages pretty rare.

I'd say the biggest reason to avoid certain TLDs is the human factor. Humans are used to typing ".com" or ".org" or ".net". I don't have any data to back that up though, so it probably isn't a satisfying answer!

[1] https://blog.nameshield.com/blog/2020/04/30/choosing-the-rig...

ccTLDs are perhaps marginally less reliable given who has overriding control over them (.ly is Libya, for example), but beyond that it's probably pretty low on your list of things to care about.