People should stop using a term 'race' for humans because there's no scientific evidence that humans have races.
Being white or black doesn't have anything to do with having different race in biology. It's just a skin color that is different.
I think the closest term for genetic and environmental (cultural?) differences in human population would be phenotype, and these definitely exist. But keep in mind I do not know much about biology, so I might be wrong here and there, I only rephrase Wikipedia.
While I dislike the concept and you're right that it's a made up construct, I need to mention that made up constructs still impact our lives. A phenotype is just a phenotype until it costs you a job or makes your home value go down. At that point, race is something you have to confront simply because racists exist.
The problem is, humans instinctually categorize people because it's easier to process. This can be as reasonable as knowing a person in a uniform works at a place, or life saving like identifying someone shady, who very well might harm you. If the phenotype of skin color ends up associated with something incorrect or misleading, however, you then have a very benign thing (appearance) leading to very real outcomes (racism).
Hope that makes sense. Race is stupid, but people judge others for all sorts of things. Otherism is very real.
My discovery about how the human cognitive system works on this some years ago has led me to the conclusion that everybody defaults to being prejudiced via this pathway - we all just assume shit about people we don't know purely based on how they look and talk - hence racism is the default.
So not being racist isn't a simple passive act of not being so, it's the active trying to stop one's natural tendency to prejudge others on how they look and prejudge entire groups of people whose "membership" is defined in our minds by things that have nothing to do with their actions or ideologies, and spotting when we do fail to stop ourselves doing it and walking back those prejudgements we made about other people.
This is why so many people who think they're not racists still go around prejudging entire groups of people, but they only do it on the positive side (ex: "Jews have Modern Values") or reserve their racism for groups against which it's not unfashionable to be racist (ex: " Muslims are violent"), when the real non-Racist posture would be to not even consider group "membership" in passing judgment, only the actions and words of the individual or ideology you're judging (so both Zionists and Islamists are violent and do not have Modern Values, because that's their ideology - something they chose, not something they were born with or into - and you can't prejudge entire ethnicities or religions based on some people in those having certain behaviours or ideologies)
Yes, we often refer it it as a heuristic because it's a mental shortcut. There are ways to counter act it, such as described in the contact hypothesis (e.g. get to know a group by having interdependence with an out group). Having a shared category with someone can also help, like being part of the same team, organization, etc.
For example, a study looked at the response rate at a sporting event when researchers approached people to participate; a black researcher and a white researcher. Under control conditions, the black researcher had a harder time getting white participants to help and to a lesser extent, vica versa. However, when they wore the same team hat, participation was close to even. The idea is, the hat showed that they belonged to the same in-group, reducting or eliminating the hesitation of participation.
I often forget author names but I can probably dig it up later. There's a lot of studies about this in social psychology since there's a general interest in getting people to stop being so damn racist, haha.
Framing it this way makes things worse, even though it's true. The focus has to be on moving towards everybody understanding, talking like, and acting like it's the bullshit that it is. We don't want to state the truth in a way that hand waves it away and centralizes the lie.
Race is a bullshit concept and we need to fix the damage caused by idiots not getting it.
I completely agree that race as an idea as steeped in false science and racism, but I always find it really difficult to consider race when it's used as a positive force as well- movements like US civil rights have massively reduced racism, partly by using race as a concept (such as black pride).
On the flip side, neoliberalism often advocates "color-blindness" as an idea (don't acknowledge/consider people's race) which is a great ideal, but in practice often seems to amount to turning a blind eye to on going racism.
Colorblindness has its roots in white settler colonialism over Native Americans, including the schools they made them go to. This helped settlers assert their claim to these lands.
That's why it's not as common in the south, where it was important to hilight race to assert control over black people.
The historical context of race is what still affects people to this day.
I think ethnicity and intersectionality are a better thing to focus on when around others (more socially acceptable and less threatening/charged), along with individual experience. Race is just one way to look at somebody but there's many many other layers and they all work together.