The tomato is not easily perennialized at this point. We don't have a good substitute. Annuals are great. We should grow the things that are annual and grow them well, but we can supplement with many other perennial vegetables.
The great advantage, to me, for perennial vegetables in cold climates, is that they're yielding much earlier in the spring. I've been eating them here in Massachusetts for a month already. They have a seasonality that is much earlier than the annual crops, so they extend the growing season in a fashion that I find is very complementary, compared with annual vegetables like tomatoes—which I appreciate and grow, by the way.