The issue with SMS even if unlimited, in Europe a lot of people need to send text messages across borders. EU mandated free roaming, which makes SMS billing under the same pricing conditions when you're roaming but doesn't say anything about sending SMS abroad when you're in your home country. Also what happens if you need to send an SMS to a Swiss or UK number?
While effectively unlimited plans do exist as carriers have stopped caring in multiple countries, this kind of friction pushed everyone to WhatsApp 15 years ago and most people won't bother checking what's included in their plan. Remember they're very cheap compared to the US, I know people paying 5€/month.
Additionally there's also the immigrant population that need to communicate with their relatives back home on other continents.
I’m surprised there wasn’t competition to deliver a better product from the telecoms. That is how we got unlimited texting and the early unlimited data plans in the US. Carrier arms race. They sure would have liked to nickel and dime but saw competition as more valuable.
RCS should have been that, but WhatsApp came out in 2009 and by 2010/2011 it was already game over in most of the world once cheaper Android smartphones became broadly available. At this point carriers' focus had shifted to data and the most pressing issue was starting the 4G rollout.
No wonder Google eventually took the RCS matter in their own hands, there was way too little incentive otherwise.
While effectively unlimited plans do exist as carriers have stopped caring in multiple countries, this kind of friction pushed everyone to WhatsApp 15 years ago and most people won't bother checking what's included in their plan. Remember they're very cheap compared to the US, I know people paying 5€/month.
Additionally there's also the immigrant population that need to communicate with their relatives back home on other continents.