You have higher costs as you manage 10+ instances.

The costs of running the instances is sunk already, because I run them on the same infra that I use for my projects, and it's not a couple of hundred dollars per month that is going to make or break things for me. The worst case scenario is "I go back to a full-time job and Communick becomes yet-again a side-project/hobby". The case where any of these instances become big enough to the point that it demands more from me is better than any of the current situation.

(begware is) another model that can also work (most of the instances have celebrated their first birthday recently).

I honestly don't see it this way. Activity through the network has been abysmal. Operating an instance at this level should be incredibly easy, but even then we have things like bigger instances having issues with lack of moderators, basic federation issues between the larger instances mostly because of network latency... all that show that we should be collectively putting a lot more resources into this if we truly want to have a credible alternative to Reddit and Facebook Groups.

If anything happened to the most popular 10 instances, Lemmy would probably die overnight.

I don't want to sound too pessimistic, but Lemmy feels pretty much dead already. My feed is mostly content from the communities that I've been posting + the two of three stubborn users (like yo)u who have been trying as hard as possible to make something out of it.