There are still important state details that aren't preserved, like how far down the page I've scrolled in an article I'm reading, a form in progress, or the text that I have highlighted in a tab. How about my active terminal sessions in iTerm? It would be a joy if that state preserved across restarts.
For example, in tab #1, I cd and run a bash script to start a web server process. In tab #2, I split it into two panes, and in #1 run workon to start a virtual environment then start the Python REPL. In pane #2, I run top.
After quitting and restarting, tab #1 returns to the proper directory but with no output. Pane #1 shows previous output and returns the proper directory but without the virtual environment activated. Pane #2 does the same. History seems to be merged across the three which is a bit confusing as well.