To me it doesn't even matter if they are babies or not, 20 weeks after conception most fetuses develop a majority of their pain receptors and many abortion methods are atrocious. I'm generally against abortion but I think it's fine in some cases.
There is no legitimate scientific support that proves a fetus can feel pain in the second half of pregnancy (as a matter of fact most neurologists agree that it is highly unlikely that pain can be felt before week 26, which is the beginning of the 3rd trimester)
but isn't it a really linear and self-focused way of thinking to take away the potential of a productive existence? especially after the fetus has developed to a certain point.
I'm not sure what you mean by 'linear' and 'self focused' in this context. Realistically every egg in the female body is 'potential productivity', on average a woman has around 300,000 eggs in her body, 90% of them will be lost by the age of 30. In america, on average every woman will give birth to two children in their entire lifetime. That's 299,998 eggs which are all 'potentially' a productive life. Nobody is worried about the potential productivity of these eggs. In regards to 'development to a certain point', 99% of all abortions are done before the 3rd trimester. Around 90% are done in the embryonic state. ~90% of these aborted pregnancies aren't even fetuses.
Most of abortions are performed in poverty stricken communities anyway. We can't determine whether or not these children will lead productive existences, and more often than not will bring burden to their perspective communities.