This is not what happens though? At one point china accepted recycling waste, but not anymore, and trash has always been to landfills. The US has well run and regulated landfills with few problems.
Yes, it is what happens. The PRC refusing to buy trash did completely overhaul the market but Vietnam and India pick up the slack https://www.theguardian.com/us-news/2019/jun/17/recycled-pla... (that article is from before the PRC stopped buying garbage but it mentions those industries)
It's also important to remember that trash isn't just from your hands to the India landfill, there's also industrial waste from the factories that make all our products that gets dumped somewhere cheap near the factory. Even if we shipped no trash to India, our consumption results in garbage dumped there because our products are made there, or near there.
Landfills are the third biggest source of methane in the US.
This is mostly food waste decomposing, which should ideally be diverted.
https://www.epa.gov/land-research/quantifying-methane-emissi...