Such downsides include:
- lower cost (.net is ~12 vs $60 for .io),
- a particular ccTLD could be terminated if the country were to change sovereignty,
- more likely to get flagged by content filters, etc.
I should add that being too affordable can also be a problem. Examples would be .info, .me and .xyz among many others were nearly given away for almost free which led to them being abused for spam/malware and thusly getting blocked by many mail providers and some firewall applications. I agree with PaulHoule that the gTLD may not have been available being one reason people use them.
[1] - https://news.ycombinator.com/item?id=33091007
[2] - https://en.wikipedia.org/wiki/Country_code_top-level_domain
Some of you might remember the incident with .io back in September, 2017.
Since then, ownership for .io passed hands and landed at Donuts who is also managing .org so I assume it's in a better shape now, but lesson was learned.
If it would be up to me again, I would push to use .io or any other vanity domain for marketing only.
The risk of a country changing sovereignty also doesn't strike me as huge. The TLD itself would be unlikely to stop existing -- .su for the Soviet Union still exists. If I've understood correctly, the administration of those country-based vanity TLDs is generally not in the hands of the country's administration anymore; they've sold the rights to someone.
If the national or territorial administration still does have control over domain registrations, I suppose they might change their minds and stop allowing them. But it'd take quite an unstable administration to just pull the plug on a well-known TLD.
The only reasons for registering a .io domain instead of using a more generic TLD might be the trendiness or coolness factor, or a geeky attraction to it. But I'm not really sure the downsides seem that huge to me either.
.dd, .cs, .yu, .oz, .su, .zr, .tp
Are some examples of ccTLD terminated.
https://www.internetx.com/en/news-detailview/these-tlds-do-n...
Also, Notion.so famously went offline because of issues with their .so ccTLD.
If I could have had .com I would have taken it. .net has always felt cheap (as in, it looks second rate) to me, just personal preference.
.io, ain't that what it's all about? Never forget a project manager getting all excited about a little drawing I made showing things going in and out of a box. To him it was a revelation. To me it was just how things work.