I don't think lemmy is still growing. I might be wrong but this graph https://fedidb.org/current-events/threadiverse
is trending down and i've seen a lot of smaller magazines/communities that haven't had any posts for 1-2weeks by now.
I try to help that problem at little but i doubt lemmy&kbin has >100k active users right now.

I won't delete my account immediately. I am concerned they will reinstate all comments in a month or so. Want to make sure they are not comming back before i delete my account.

According to the graph it accounts for active users within the last 30 days. 30Days ago the reddit strike started and an influx of people started posting. I wouldn't be surprised if a lot of people haven't been here since. There was a lot of performance and other issues with lemmy&kbin at that time.

It's gonna be a while before this is implemented. We also have to unify on rail gauge, electricity delivery & control system. While there is ongoing efforts to unify all of those system, it will probably be decades before we will be able to propertly utilize any new high speed rail lines from this proposal. Always a good idea to improve things for the next generation.