I have been working mostly with ChatGPT. I've found that it is much easier to move things around, back and forth, copy and paste, etc. within my desktop system (Windows) than on my smartphone (Android). In fact, I've been unable to figure out how to copy and paste text from within a chat message. I've taken to asking questions on the phone when I'm out and about but come back to my desk to do any processing or manipulation of the text.
Then you should be able to hold your finger anywhere on a message for a second or two, and get a popup menu with "Copy" (copy the whole message) and "Select Text" (you can highlight just a portion of the message to copy).
Similarly, if you've copied something, you should be able to hold for a second or two on the "Ask anything" text input box and get a "Paste" button to paste.
I have been working mostly with ChatGPT. I've found that it is much easier to move things around, back and forth, copy and paste, etc. within my desktop system (Windows) than on my smartphone (Android). In fact, I've been unable to figure out how to copy and paste text from within a chat message. I've taken to asking questions on the phone when I'm out and about but come back to my desk to do any processing or manipulation of the text.
Yep, computer's easier for copy/paste. However, it still shouldn't be too hard on your Android.
(Edit to add: the following currently doesn't work for me, even though it used to! I think it's a bug, I hope they get it fixed!)
Make sure you're using the official ChatGPT app from the Play store, https://play.google.com/store/apps/details?id=com.openai.chatgpt
Then you should be able to hold your finger anywhere on a message for a second or two, and get a popup menu with "Copy" (copy the whole message) and "Select Text" (you can highlight just a portion of the message to copy).
Similarly, if you've copied something, you should be able to hold for a second or two on the "Ask anything" text input box and get a "Paste" button to paste.