Considering that there are at least a gazillion texting apps, I just don't get excited about Google's.
Use Signal, and make it your default.
It's not a bad suggestion, and I personally think that Google's app is rather rubbish. But Signal has the same problem as other internet-based messaging apps: you need everyone you want to message to use it (a problem known as the "network effect", which make it very hard to displace incumbents once they become dominant - something key to the big tech companies' business models).
That's where SMS wins, because it's a standard that everyone has access to. Of course Signal can work as an SMS client, but frankly there are better SMS clients so I use Signal only for Signal messaging. That's also why Apple see iMessage as an advantage (because all iDevice users have it, and it's better than SMS), it's what Google were hoping RCS would do (if you can get it on all devices and networks by default then you have the universality of SMS but with better features plus you weaken Apple's iMessage lock-in, which is also why Apple won't support RCS on their devices).
The truth is that it's probably too late to improve this situation. The universal solutions (SMS, MMS) are limited (and the fact that in my country some carriers still charge through the nose for MMS makes it particularly unattractive), and the better solutions are fragmented. And with no standards body mandating a better upgrade to SMS/MMS (which, with the plethora of other messaging apps, is I suspect too late anyway) we seem for the time being to be stuck with the current situation of a mess of mutually-incompatible messaging services. I think the best we can realistically hope for is that Facebook are forced to sell WhatsApp at some point, which would at least introduce some diversity of ownership (since outside of China the messaging app market is totally dominated by WhatsApp and FB Messenger. And of course FB understand what network effects mean here, which is why they bought WhatsApp to avoid the risk of getting stuck as a niche player themselves).
