Say you’ve been working somewhere for 5 years and have the opportunity to move to a company - and you know both companies are laying people off at some point soon.

In your current company, maintaining your position requires no training and negligible HR resource. The question of your capability to perform the job you’re given would hopefully not be under question (otherwise good going for keeping that gig up for 5 years). Your team is not a blue sky project (otherwise shame on management for keeping that gig up for 5 years). Making you redundant will cost the company severance, and if it’s a structural issue you could be moved into another team. Dropping you would be a genuinely hard decision.

The new company barely know you and have to expend resources just to integrate you, and expend nothing to drop you.

I know which one I’d pick.

Granted, it’s a false premise: perhaps the new company is more resilient than your current company, for example. However, if the odds are unknown - and in most cases they aren’t known in any reliable way - then I may as well treat them as if the odds are balanced.