Tevye's oldest daughter sets the example for the rest of her sisters by rejecting a wealthy but yucky arranged marriage in favor of a poor local tailor that she loves.
Here we have the best-case scenario for what happens if you throw away the whole arranged marriage thing and make your own decision about your future. She might shock her dad by announcing that she would rather be a servant than marry grody old Lazer-Wolf, but Tzeitl still gets off pretty much scot-free.
Motl the tailor is a good and decent dude, and their true love for each other seems to really help them through the relative poverty that they experience. Check out their mega-happy ending:
The couple, blessed be His name, is living happily. He is a tailor, goes around Boiberik from one dacha to the next picking up work, while she is busy day and night cooking and baking and washing and scrubbing, carrying water from the well, barely a piece of bread in the house. […] I talk with her, and she says she is happy as can be as long as her Motl is healthy. (4.146)
So, besides the spooky foreshadowing that Motl (spoiler alert) might not be so healthy down the road, what's awesome here is that even though Tevye is kind of teasing the two of them for being so poor, he describes their life like an updated version of what Tevye and Golde have. They've got a partnership and divided responsibilities, just like Tzeitl's parents.
But notice that we never really see Golde's point of view about Tevye (although we sure can hazard a guess about how she feels, especially after he loses all their money… ). With Tzeitl, we actually get her perspective on the marriage, even if it's still filtered through Tevye's voice. The fact that we're seeing stuff through her eyes already shows how much more equal their relationship is—definitely an improvement, we would say, over what she grew up with.
"Improvement" is really all it is, though. Compared to her sisters, Tzeitl just takes a teeny baby step in the direction of the future. After all, Motl is Jewish, is a local boy, and he still comes to ask Tevye for permission. Except for the forget-the-matchmaker business, not all that far removed from what would have happened in Tevye's own generation.