I start by looking into Hangouts matters, because I use Hangouts to talk to some of my family, currently only on my phone and not on my laptop; and I see three projects listed in https://matrix.org/docs/projects/try-matrix-now: matrix-appservice-hangouts, mautrix-hangouts, and Hangouts Bridge. https://matrix.org/docs/projects/bridges/#hangouts lists two, matrix-puppet-hangouts and matrix-appservice-hangouts.
Bridge, puppeting bridge, appservice—I have no idea what any of this means. I’m generally hoping for something like an instruction to install a piece of software on my laptop with `curl … | sudo bash` or some unsigned .exe or something. (Are any of these things basically a Matrix server that I could run on localhost, or do they slot into a Matrix server that I’d need to host elsewhere?)
And so I give up. The content formatting of those pages on matrix.org was super-ugly anyway, it’s clearly either not a good product or not for normal people. (This remark may seem harsh, but this is how most will think.)
What do I need to do for all of this to get Hangouts, SMS and Slack working in Matrix? Is Matrix ever going to focus on users and make questions like this easier to answer, or will it remain a niche product that I should not bother with?
For certain things it's pretty easy. Bridges like IRC, Gitter, and Slack are a couple clicks from within the Riot app, although you do have to go goof around in the settings for those third party services to get it talking to Matrix. There's also starting to be some hosted services for bridging public rooms where you can just invite the bridge bot to the room to get things going. Like here: https://t2bot.io
The thing that I find particularly exciting about Matrix is that it 1) has support for doing that kind of thing, and 2) it can scale pretty gracefully from a 1-to-1 chat all the way up to a room with thousands of users. So you can (even if it isn't always easy, currently) bridge a 1-to-1 Hangouts chat, or a Slack room with a few dozen people, or a Discord server with thousands.
I'm not trying to oversell it right now. Many of the bridges are difficult to set up and not really something the average user will be able to do (although there are many that are). But it's pretty damn cool that we're able to do it, and I expect it to get easier as things progress. Matrix itself is only just now leaving beta, and even then the reference server is slow and still missing some big features. So the "extra" stuff written by the community is going to take a while to develop into "click to enable".
Given that the documentation you're reading is for sysadmins, it shouldn't be a surprise that its not targeted to end-users (assuming that is what you meant by "normal people")
> but it’s only a killer feature if it’s accessible.
Again, depends on your definition of accessible. Personally, if there is a feature I really like, I don't mind being patient and spending couple of hours to understand the docs.
I'm not denying that Matrix needs to improve the issues that you've pointed out, but that shouldn't make one disregard how useful it is.
Dont underestimate the value of a easy user interface for a products success.