While the most recent round of changes were meant to improve the chances of successful site proposals, I feel it's useful to revisit it.
We're past the point of rapid growth in site numbers - and a significant number of new sites seem to be related to cryptocurrency. While I'm not going to comment on the viability of these sites - to some extent, the current model tends to encourage specialised sites, with knowledge siloed out, and generally there's a lower chance of more generalist sites.
Fundamentally - our current model encourages niche sites (and from the occasional attempts at bootstrapping sites with puppet accounts - there's still a certain cachet to having a SE site), and there's a certain difficulty/unwillingness to propose more general sites - which might lead to both more quality Q&A as well as broader reach.
In some cases - the viability of a specialist site might not be dependent on interest - Windows Phone is currently a ghost town, not due to lack of enthusiasm by its fans, but rather because the parent company of the product killed it off. A more general site might be better for these.
While its a little late for a grand unified cryptocurrency or mobile-tech site - I wonder if there's areas of interest to the tech/SE community that we're not covering and if we could work out ways to build viable sites. Things like smart TVs and other appliances don't really have good homes on the network, and we're in an age where people might want to work out why their washing machine is uploading a gig of data a day.
For niche topics - at this point nearly anyone can spin up a small/private Q&A instance via Teams - could a viable site be proof of concepted there? While there's no migration, it would still prove the viability and show what sort of questions/scope might work.
Fundamentally - could the company and community identify generalist topics we can build new communities around - and figure out ways to cluster and direct niche communities to existing/shared resources to better meet their needs?
In a sense - could we change our model of community creation from staking a claim to building planned communities to help fill gaps in support?