I moved from a small city apartment (maybe 50sqm) to an old country house, about 240sqm. I've had partners here and there but mostly it's me and my cat.
I was inspired by the Solarians from Asimov's Foundation series - currently working on the fleets of robots to cater to my whims.
Certainly came in useful during 2020 with the pandemic and lockdowns, with the nearest neighbours being 500m away as well.
When Atlassian Hipchat shutdown/moved everyone to slack, I evaluated Matrix and Mattermost. I did prefer Matrix because of Federation, but Mattermost won out because it had more out of the box integration with our dev tooling - Jira, Gitlab, CI, etc..
I don't think Mattermost has E2E encryption, only "encryption in transit" and "encryption at rest", would probably make it difficult for public room search/indexing etc so maybe outside it's use case?