UK forestry (as far as I've seen) mostly consists of felling sitka spruce and lodgepole pine monocultures that were planted right after WW2 and never taken care of again. As a result the wood is shit quality and mostly goes for pulp/chipboard or biomass.

Higher grades of timber need to have straight grain and less knots, so that is achieved by selectively thinning out the forest maybe every 10 years, and pruning off lower branches. But this adds a lot of man-hours and cost, so I've never seen anyone doing that in UK. Tbf I haven't been around the industry at all since COVID, and the price of timber went up so much maybe things are changing.