Married, we both work from home, and we’re in an apartment.
First, all of my weird stuff is not between her work and living room pcs and the internet. Cable modem connects to normal consumer router (openwrt) with four lan ports. Two of those are directly connected to her machines (requiring a 150-ish foot cable for one), and two connect to my stuff. All of my stuff can be down and she still has internet.
Second, no rack mount servers with loud fans, mid tower cases only. Through command line tools I’ve found some of these are in fact capable of a lot of fan noise, but this never happens in normal operation so she’s fine with it.
Separately I’d say, have a plan for what she will need if something happens to you. Precious memories, backups, your utility and service accounts, etc. should remain accessible to her if you’re gone and everything is powered off - but not accessible to a burglar. Ideally label and structure things so a future internet installer can ignore your stuff and set her up with normal consumer internet after your business internet account is shut off.
Also keep in mind if you both switch over so every movie and show you watch only ever comes from Plex (which we both like), in an extended power outage situation all of your media will be inaccessible. It might be good to save a few emergency-entertainment shows to storage you can browse from your phone, usb or iXpand drive you can plug directly into your phone for example.
I’ve been ranting about this a lot lately, but as the owner of mspencer.net (completely useless personal domain, but is 199 days older than wikipedia.org for what it’s worth)…
There is sort of a way to do that, but it’s still labor intensive so not a lot of people do it. Movements to investigate are homelab and selfhosted. Homelab equipment is old (extra power-hungry for the capability you get) or expensive. Self hosting requires a bunch of work to stand things up the way you want it.
Biggest barriers to self hosting - or hosting through your nearest nerdy relative - are the following:
Free ad-supported offerings (with the privacy and terms and conditions impacts you describe) are better and easier, so they out compete DIY options. If a nerdy family member offers to host forums and chat for your community club or whatever, the common response isn’t gratitude, it’s “That’s stupid, I’ll just use Facebook.” Without that need and attention, volunteer projects get way fewer eyeballs and volunteers are way less motivated.
Security is difficult to figure out. Project volunteers have enough on their plate just helping users get their stuff working at all. Helping novice users secure their installations is so much extra work.
Many volunteers feel taken advantage of if they produce something that could help companies make money better, when they don’t share any of the money they make through donations or support arrangements. Similarly, many open source projects get taken over by for-profit companies who diminish efforts to make their open source offerings easier to use for free. (They want companies to buy support contracts, even if it means frustrating use by private individuals without kilobucks to spare.)