Well, on the one hand that means an expanded gene pool, and that is great, because generally this means greater potential for adaptation, and a lower risk of total species loss due to an over concentrated gene pool.

On the other hand, resources only diminish as time wears on, and people need those. The more people, the more resources are needed, the faster those resources get used up, the harder it becomes to locate required resources... Theres a whole doom spiral associated with that.

Then there is the environment itself, which, if current scientific consensus is something you care about, seems to point toward the human race being the biggest threat to itself or its habitat, although the threat we pose COULD be diminished, without diminishing our numbers. It would only require the end of for profit energy generation, end the use of combustibles as fuel for energy generation, massive advances in fusion technology, renewables and other things that don't get the funding they need because of politics and financial cartel operations.