If there was a realistic chance that Litvishe boys would start dating at 19 years old we could talk about it. However that isn’t likely to happen in my or you lifetime for various reasons…. starting with the fact that the Roshei Yeshiva/Daas Torah don’t think it’s a good idea.
To encourage the boys to date slightly earlier, perhaps return from EY slightly earlier-Yeah that’s realistic and will probably start happening….
I am on the bandwagon of promoting what can and is realistic to be achieved (and only that which is endorsed by leading Roshei Yeshiva).