VP is also president of the US Senate but I haven't seen much, if anything about her casting tie-breaking votes- I remember seeing this when Biden was VP. Pence would have been on a short leash.
I found one site about VPs and it mentioned Harris' "decisive vote' on the American Rescue Plan that won 219-212. Not seeing how it was 'decisive'.
VPs are often 'under the radar'.
The first link you posted contains "The Biden administration is looking at how it can apply its
plan to tackle root causes of migration to the hemisphere, like matching people to jobs where there are labor shortages in the region, a senior administration official told CNN."- the US has tens of millions who don't work; how is adding millions to the population a good thing?
I'm not going to sign up in order to read the second link but in searching for 'Kamala Harris accomplishments', I saw more than one mention of her interview with Lester Holt (NBC) where she downplayed the urgency of the Guatamala/Mexico visit.
Look at the number of border crossings since Biden was elected and ask yourself "What has been done about this?".