[CW: racism]
People who are worried about people not having children and almost 100% doing so for racist reasons (not enough 'white' babies to outcompete the 'brown immagrants breeding like rabbits'). That, or they're the insane capitalist 'infinate growth' Musk types that are wanting more disposable workers. Usually it's both.
The "there's too many people" types are usually middle class. They see the damage that the rabid consumption has done to our planet, as well as our mental health, and have come to the incorrect conclusion that it's due to there being "too many people". Being middle class and fed a diet of neoliberal eugenic classism, the people that they think there are "too many" of tends to be uneducated lower class people who they deem as "idiots". They're usually the type to believe that idiocy and criminality is genetic and that those are the ones we should get rid of. The problem with this outlook is it assumes that our rate of consumption is largely due to our population size, which is incorrect. We consume far more than our population needs (and waste a large amount) due to capitalism's wasteful and inefficient management of resources. It also ignore the role material conditions have on people.
The real answer is that population growth is largely dependant on material conditions. Humans are social animals that are supposed to live in a community. Capitalism has destroyed this and atomised us. Now all we have are ourselves and direct family, meaning each of us is expected to have children. This is not how we do things when we live normally. In a normal human community we don't all have to have children. We help raise each other's children, we are one big family, "It takes a village" after all. Our rate of population growth becomes dependant on our environment and naturally slows when there are enough of us or increases if we are dying out.
If we were to manage our resources in an efficient, non-capitalist way, where everyone got what they needed and we built in a way that doesn't fuck our environment, and if we didn't expect everyone to have kids and instead raised children communally as one big family, we would be fine.
To answer your question: It's neither. It's only "bad" or "good" because of capitalisms wasteful nature and need to consume everything.