> Eliminate the side effect via birth control and people can now have sex for pleasure with no side effects.

And that's not a bad thing. People used to have babies even if they were nowhere near ready for it by age, emotionally, financially or in terms of housing. Particularly teen pregnancies have a massive cost on society and reinforce generational poverty.

If governments would actually want more children, they'd lower the working hours so that both parents can stay employed while being actually able to raise their children adequately (no, handing off your kids at 7 in the morning and getting them back at 6 in the evening, only to have maybe an hour of actual time with them before they have to sleep is not raising children adequately), they'd provide families with housing, they'd provide mothers with affordable healthcare instead of five figures worth of hospital bills in the US, they'd provide both parents with parental leave instead of forcing them to juggle work and adjusting to care for a toddler...

Young people everywhere see how unimportant they are to society and are resisting to fall into the same trap their parents did.