keverets
There are other proprietary services which can do the same for no monetary cost (usually lots of advertising and tracking, though).
It's not as slick as the official app, but requires much less in the way of permissions and is more flexible.
I use both. Conversations works well out-of-the-box on Android. I use Vector on my desktop, Matrix Console Android, and Vector Android, but none of them work very smoothly. I'm hopeful they will improve as time goes on as I tend to use XMPP more since I have more personal contacts that I can communicate with via that protocol, but I also like and use Matrix.
You don't seem to be aware, but there was an XMPP<->IRC bridge long before Matrix existed. It was about as satisfying as the Matrix version, though that's still improving.
I'm running my own matrix server (synapse), and my own XMPP server (ejabberd), and honestly ejabberd was easier to get off the ground. Again, I'm hopeful that synapse will improve with time, but I really think there's room for both to exist since they do have slightly different use cases.
The author of Conversations recently wrote up the state of XMPP in 2016: https://gultsch.de/xmpp_2016.html
So, though you may not be using it anymore, XMPP is far from a dead end.
Though it's not web based like imo.im, you also don't have to give your access credentials to a third party.
I'm speaking from being a peer; both a consumer and a supplier at the same time. We are more than consumers, we're people and citizens that provide services and utilize services of others. Having a third party in those transactions that can arbitrarily disrupt them has proven problematic (for reference, see all of the backlash against PayPal for the way they arbitrarily freeze funds on both sides, etc).
I would love to be able to pay for goods on Amazon with bitcoin, because I trust Amazon. Right now Mastercard/Visa/Paypal takes a cut on each of those transactions to provide "trust" in them that I neither need nor want. If things go wrong in that transaction, I'm still left dealing with Amazon, as Mastercard/Visa/Paypal will not want to get involved.
In cases where you're dealing with an unknown quantity, then you have to look elsewhere for your trust metric. eBay has their, eg. "99% positive" reviews, Silk Road has their own way of dealing with this (similar with freebies/samples to build trust).
The use of Paypal and credit cards destroy this trust by allowing a paying party to reverse transactions so the payee gets nothing. It's empowering a third party to arbitrarily negate charges.
Bitcoin is no more a "den of thieves" than a cash-based society, which most of the world was until recently. I'd argue that Credit Cards and PayPal are much more a den of thieves by abusing their trust to cause no end of issues for people receiving payments.