You said you're not an expert, and that's okay. You don't have the context to understand what you're asking or why it's even an issue when it sounds so simple.
My day job is teaching college courses in computer science, discrete mathematics, and UI/UX design. Here's my opinion on the subject.
That I or any other half competent programmer could think of easy ways to implement 99% of the feature requests people post to this forum is irrelevant. The devs have far stricter standards and protocols regarding changes to the memory structure and you're not going to convince them to change anything by making false analogies or appealing to "but it would be optional so it doesn't affect you if you don't want it". Every feature addition affects everyone, even if it's an optional feature that people can turn off, because (1) they have to program everything with the assumption that there will be players on minimum spec machines playing with every UI option turned on, and (2) because it affects what other decisions they're willing or even able to make regarding the UI or memory structure.
It's fine to want speech bubbles and to ask for them on the forums. But when those of us with programming experience and who have been keeping up with dev letters and interviews for the last decade tell you they probably won't devote resources to it right now, we're not just trying to be contrary for the sake of shooting down your idea.
There are real UI/UX problems that make the game unnecessarily more difficult or frustrating for people, such as the non-customizability of the hotbar when you're playing as a story character; or that side content that was made MSQ-required after the fact still use optional content quest icons instead of required content quest icons; or the lack of effective colorblindness accessibility options. Chat bubbles are just an immersion or convenience feature. If I were working on a game like this, I would fix those other problems before even entertaining the idea of chat bubbles.