Being in my 60s, I have seen the 'before' and 'after' pics of a population about doubling over my lifetime. Many things have improved, many things are worse. Population stresses infrastructure, stresses societal behavior, increases competition for resources.
Agricultural technologies, increased energy production and associated efficiency technology, and communications systems have enabled humans to increase beyond their individual capabilities; otherwise the planet's natural processes and delimiters would have killed enough humans to stabilize.
I do not see "loads of people" working on population problems. I do see some people working on the problems caused by an excessive human population - but only those problems where there is a quick profit.