Rabbi Aryeh Lebowitz

So he says, Therefore, you want to have a Talas Gadol so that you know it's for sure Chayiv and Tzitzis, and you wear that during Chachris, and you wear a Talas Katon throughout the day so that you're never without Tzitzis at all, but at least when you're going to say a bracha, and when you're davening, you should have a Talas Gadol.

Davening is also a time of extra Yerushalayim.

The Beis Yosef in Simuchas writes that covering our heads...

humbles us and makes clear when it describes that his mother insisted that he have a head covering in order to generate so the talus is used for Natifa to wrap one's head and that generates an extra sense of Yerushalayim.

and which seems entirely appropriate for tefillah.

And there are also times during davening when tzitzit comes in very handy, that tzitzit plays a particular role at different times during davening.

The Gemara in Bracha, Stavya Dalet says, that a person who says kriyashma without tefillin, it's as if he's being made a shaker on himself.

But the Zohar in Parsha Shalach writes,

that if you say that it's so in that context that when people are traveling they just think it's too much to slurp along their talus gadol not right you should daven with the talus gadol

Because you're going to be Korah Kriyashma, so you should have a talis kadol, you should have a talis when you do so.

The Shulchan Aruch in Simchan Chavdal writes, When you get to Rissamos and Kriyashma, there's a minag.

to look at the tzitzis.

And some have the minute to kiss the tzitzis.

All things that are difficult to do if you're not at least wearing tzitzis during davening.

And it's even easier if you're wearing a talus gadol during davening to have access to your tzitzis.

In Simeon Yud Zayin Tziv Gimel, the Shulchan Orek says, When a child is old enough to know how to do an atifa, the father should buy him tzitzis to be mechanichim.

What is Yodel, this atif?

So the Ramad defines it.

He knows, and he can grab them in his hands.

So again, all of this highlights that