Things are going to be tough - there is no doubt about that, but I think the same will be said about many other countries. A lot of the issues you mention are not unique to the U.K.
And there are still companies investing or growing their operations in the UK. You only have to look at Shell relocating it’s HQ to London from the Netherlands.
But the legal industry is one of the great stabilisers to the U.K. economy, and I don’t see that changing. A lot of the world like using our legal system for their global entities. It’s probably the second most used jurisdiction in the world after the US.
And many firms are kept busy by the bad times as much as they are the good. And they need lawyers to do that counter-cyclical work.
Finally, too many firms have been burnt in the past by cutting their trainee intakes and then not having enough NQs when markets pick up. Trainees are much cheaper than qualified lawyers, and so hedging your bets and keeping trainees is generally a much cheaper option. If anyone gets laid off it will be the mid level associates rather than the trainees.
By the time you started your training contract, the U.K. is likely to be a different set up. Most likely we will see a Labour government in charge and I suspect things will be a little more rosey than they are now. By the time you qualify, it is likely the UK economy will be picking up and in a period of growth.
Will there be better opportunities elsewhere? Undoubtedly. But the great thing about being an English qualified lawyer is that it can take you a lot of places. The same can’t be said for a lot of other jurisdictions.