Is it true that plants absorb less CO2 now?

Guys, you're on the right track. So, from what I see in my garden and what I read, the situation is more nuanced than a simple "plants absorb less CO2". Individual plants haven't lost the ability to absorb carbon dioxide, actually in some cases with more CO2 in the atmosphere they could theoretically make greater use of it. The real problem is that we've drastically reduced the surface area of plants and trees on the planet, so even if each individual plant is working well, overall we're losing absorption capacity because there are fewer of them.

I'll add something I'm noticing in my own small way too: ecosystems are suffering a lot. I've seen over the past few years how plants are more stressed by prolonged droughts, extreme temperatures, pests we didn't have before. When a plant is stressed, it still absorbs CO2 but grows more slowly and isn't as efficient as it should be. So yeah, in theory they keep doing their job, but the overall quality and quantity of what they absorb has actually decreased, not so much from loss of capacity as from reduction in biomass and stress conditions. It's a combined effect: fewer plants + plants that are suffering = less CO2 removed from the atmosphere compared to what we could be doing if we still had the intact ecosystems from 50 years ago.