Having never noticed DRLs in bright and sunny Texas, one of three things must be true:

1. People in Texas don't have them.

2. People in Texas have them, but they don't make cars any more visible (as I would have seen them).

3. People in Texas have them and they make cars more visible, but I'm not a very observant driver (which I don’t think is the case, but who thinks they’re unobservant?).

Unfortunately, I really cannot comment much beyond the above.