Google Messages

It's absolutely unfortunate that right now, this is the only messenger app with end-to-end encryption... but only between two people using Google Messages. (If you're texting an iOS user, the messages won't actually be encrypted despite Apple using RCS along with Google.) Being a Google app, it takes its toll in terms of privacy (meaning it's just bad at it). It's even worse in terms of security mostly thanks to SMS still being a thing. Unfortunately, that's what most Android messenger apps still use since it remains the only communication system widely available (as far as I know). Signal, SimpleX, and other more secure messaging apps don't use that communication system.

It does have a positive in that it allows you to use it on the web (on a PC browser), and without logging in to Google via device pairing. Won't be much use for me unfortunately since I'm blocked from accessing Google-owned domains on my computer (for now).

I'll TL;DR on this one btw: If you care about secure messages between friends and family, stick with Google Messages. If you care about distancing yourself from Google at the cost of using SMS instead, I'd suggest you find an open-source messenger app for the job (such as Fossify).

Closed source and owned by Google

Works ok for SMS features, but constant push to use "Rich Messages" RCS protocol, which it confusingly doesn't call RCS are annoying(It calls it simply 'Messages with chat features). The buttons for those questions are placed in such a way that it's easy to enable RCS, when you don't want to use it.

Preinstalled on android, Easy to use, has dark mode, message for web

I am happy with the app on my mobile phone. However, the "messages for web" feature, which allows one to read and send messages from a computer web browser and which is very important to me, requires constant re-connection via scanning a QR code on the computer screen from within the phone app. Quite frequently the result of attempting to reconnect like this is, "Something went wrong. Try again in a few minutes." Unfortunately waiting a few minutes rarely is sufficient and I have been unable to determine what actions ARE sufficient to get this working again. This has been an outstanding issue for the last six months on Google's support site with no adequate response from Google in that time.