I respect the woodland trust and volunteer for their tree planting, but I thought that press release was a bit negative. It showed that new woodlands had increased from 5.5kha in 2016 to 13.5kha in both 2019 and 2020 which seems like a good increase to me.

There are advantages to natural regeneration*, but the majority of the new tree woodland creation in the UK will continue to be commercial forestry companies making dense plantations of non-native Sitka spruces in Scotland. They're not great for wildlife, but they do grow fast and absorb carbon which is good, so long as they aren't on peat habitat like the last time the UK had a tree planting boom. The speed at which the companies do this will depend on their economics of buying the land vs the expected market for the product.

* https://www.theguardian.com/environment/2020/dec/15/restore-uk-woodland-trees-report-rewilding-britain