If working for big tech is what youbwant to do, there's no such thing as a bad time to go for it. That said, you'll have a harder time finding opportunities in this currently bout of layoffs and hiring freezes than you would have this time last year.
My advice is think about what you want to do day in and day out, rather than just focusing on "big tech". There's plenty of coding roles outside of big tech, and a lot of industry jobs haven't been affected by layoffs. If you love working on web apps or data processing (eg) you don't need to restrict yourself to big tech in order to get paid for that.