Hopefully the EU (or, in an alternate reality, the US) will eventually force Apple to finally implement RCS messages (or, less likely, open up iMessage).
Why? No one uses RCS in the EU, who would Apple users talk to?
Lots of providers implement RCS, lots of people use it. Perhaps none of the people in your particular region/circle of contacts do? My contacts almost all use signal. The exceptions where there are people that don't have any third party messaging apps, they use RCS. To those people, it's "just like a better MMS", they don't know any different, it just improves their messaging with no effort.
At least for the region I know, there are _a lot_ more Android users than iOS users, and third party messaging is really common. In practice, SMS is the last resort if you have nothing else.