Conversation view is an awesome feature in Gmail that groups an email chain of replies into a single conversation, cleaning up your inbox and putting relevant emails into one place. However, not everyone likes conversation view.
You could always turn it off on the web version of Gmail, but not the mobile version. Google has now fixed that and you can disable it in the iOS and Android apps.
Disabling the feature on the web version will do the same for the mobile apps. You can’t separately enable and disable them, but for those rare people who don’t like the feature, this is likely not a problem. It’s good to have options, even if few will use them. The update is rolling out over the next two weeks so give it a shot!