People talk about the benefits of a functional architecture with UIs and how I guess you can see it as a data stream where FP helps think about things, but sure

People talk about the benefits of a functional architecture with UIs and how I guess you can see it as a data stream where FP helps think about things, but surely Smalltalk-style OO with messages would be the best way to represent something that both requires a lot of back-and-forth but also widget state? Are there any OO-style web frameworks that are popular nowadays?