The last Laravel project I used was using Livewire V2.
Not all of the problems were strictly "Livewire" problems, but also just the limitations of PHP. Having to send the state back and forward and rehydrate the state on the server on every request is just slow no matter what you do. Live View has an active process for every connected user that maintains state so you only have to send tiny little diff's back and forward.
Do LiveWire responses get so big that the size becomes an issue?
Haven't used either LiveWire or LiveViews seriously. Honestly trying to understand what you're saying.
I was under the impression LiveWire only sent the data for the component being updated so realistically the main issue is latency (just as with LiveViews).
I mean, sending 0.1kB vs 1kB is 10x worse but in practice this doesn't seem like it would have a real impact in UX for the majority of use cases.
Livewire has to send the full state of the request for the component. Search results is a good example where the state can start to get big. Once it hits the server re-hydrates the models. They are also HTTP requests which have some handshaking.
Live View only sends the diffs excuse the state lives in an active process on the server, and it uses web sockets which is much faster than http requests.