Indeed. Pretty much everyone I know is "texting" with their friends and using whatever is the default app on their phone. Some people will use Whatsapp for specific groups/events, but that default text app is very commonly used.
This reminds me of a conversation with an iPhone-using elderly relative who wanted to text friends in their retirement home:
ER: Why is it that when I send text messages to my friends they sometimes never get them?
Me: When you get messages are the bubbles green?
ER: Yes.
Me: Is there bad phone signal in this area?
ER: Yes.
Me: OK, that means your friends are using Android phones, so your messages are being sent by a method called 'SMS' which isn't very reliable, particularly when phone signal is poor.
ER: I don't really understand that. What I can I do to fix it?
Me: You and your friends could install an app such as Whatsapp or Signal and send your texts with that.
ER: No, I'm not installing an app!
Me: You could persuade your friends to buy iPhones.
ER: They won't do that.
Me: You could wait a few months and Apple will most likely activate a new system called "RCS" on iPhones which might make messages with your friends a bit more reliable.
ER: That's no good, I need to fix it now.
etc. etc.