It’s a quite entitled view to take that they should make an effort to pass the project on. It would be very hard to build sufficient trust in a new developer quickly, and passing it on without that trust would be undermining the trust that users of the projects have placed in this dev. If I were him, I wouldn’t be staking my reputation on finding someone to take over from me if there wasn’t already an obvious candidate.

The successful fundraiser you mention looks to have had a target of $12k USD (from: https://discuss.techlore.tech/t/divestos-is-unsustainable-needs-community-support-we-sent-250-and-you-can-help-too/6660, the original page has been taken down), and was as a alternative to them taking a full time job. I’d say its a reasonable bet that money was spent on living expenses, and IMO $12k a year is much less than this level of skilled work is worth. It’s certainly not enough money to make it unreasonable to shut down the project a year later, and I doubt anyone who donated feels shortchanged by it.

Why would it need 5GHz? At most it needs to do two audio streams, which aren’t going to need lots of bandwidth

The upside of IANA doing it would be a standardised place for sites to move to. Without coordination, different sites would move to different TLDs, probably mostly based on what isn’t already registered. IANA could create a new TLD for this and give existing whatever.io owners a chance to register whatever.iox before its generally available