LTE is not as important as you make it sound.
Mobile bandwidth is still expensive, so you only get a couple of GB per month for a decent price and if you want more, you have to shell out a lot of cash.
I don't know how it is in the US, but here in Europe (at least in my country, Romania), the 3G connections are pretty good and 4G is coming, but it's not there yet.
And I can't picture what you'd want to do with an expensive 4G connection. With my 3G connection I can watch Youtube videos just fine. But it really does work at around ~ 20 Mbps (HSPA+), which is like ~ 2 MB/s, so if I'm not careful, I can burn thorough my 5 GB plan in a couple of hours. And from personal experience, few people have more than 5 GB of monthly bandwidth.
At home I have Wifi, at work I have Wifi, all the coffee-shops I go to have free Wifis for clients, most hotels have Wifis too. The only instances where I use my 3G connection is when I commute between places or if I end-up with a shitty Wifi connection and in such instances I just browse the web casually, or read email, or read Twitter/Facebook updates. Which is what most people do.
The only heavy-usage of my 3G connection has been for Skype. But Skype works surprisingly well for me over 3G (YMMV of course).