I mean, we are overpopulated

No. The problem ISN’T that there’s too many people. The problem is that rich people and rich countries are hogging almost all the resources so there’s not enough to go around.

You’re doing exactly what the meme is warning against.

the solution is just to have fewer kids

While that’s probably a good idea for most on the micro (specific family) scale, on a macro (country, continent, planet) scale, it does almost nothing compared to better resource distribution.

us older folks will suffer the consequences of less young people to care for us in our old age

That’s ALSO more of a distribution problem: with better compensation and working conditions, more people of all ages who are themselves healthy enough to do the job would care for seniors professionally, and with better social service budgets, more seniors would be able to afford it.

Moreover, people in other professions having fewer working hours and better pay per hour would allow them the time and economic breathing room to better care for their family members in their free time, which would mean fewer offspring per family would be needed for it

but after that’s over, things could be pretty nice for the planet.

No. The resource hogging rich people would still be poisoning everything by perpetuating reliance on fossil fuels and other genocidal economic behaviors.

Every single problem attributed to overpopulation can be solved by distributing resources away from corporations and billionaires towards things that actually improve the well-being of humans in general AND the planet.

Pretending otherwise is helping the oppressive elite whether you intend to or not.