What you are missing is the industrial scale horticulture required for fruit and vegetable production, which is largely under vast swathes of poly tunnels and glass houses around the world, some heated, generating vast amounts of CO2 in their manufacture and construction, as well as ongoing running, with no real way of recycling them yet.
Then you have to consider the huge amounts of water consumed, often in 3rd or developing works countries that already struggle with water. The export, airfreight cash is too much to ignore. But the privileged few in the developed world see no harm in exporting that problem.
And then there’s the way that the vast amounts of people that are needed in this system are treated. The lucky ones are transported to Europe, the US and the UK to work on farms doing back breaking work for minimum wage, staying in caravans or worse, with no guarantee of work day in day out. The unlucky ones do the same job for a 10th of the money or less in their own country. Treated not so differently to those on plantations in bygone years really.
All so we have avocados, strawberrys, beans, peas, flowers, you name it 365 days a week on a supermarket shelf. And for nearly a third of what’s grown and imported to end up as good waste. Give me local, seasonal produce, including meat, game and fish, any day over the industrial scale abuse of people any day.