A good decade ago I quit one job (wasn't particularly unhappy with it mind) to go to another (same job effectively, just abroad and less tax), and then before I went to the other an even better opportunity arose, and that opportunity has compounded since.
For an average earner, if people can build up 3 months earnings, as savings (or even re-mortgage to free up some cash), then this will really help enable people to take more opportunities, which may only appear at last minute. Even 3 months of costs covered, for absolute bare necessities could do it. Those bare necessities to be wouldn't include boozing, Sky TV, Holidays, fancy clothes etc, put those on hold for the short term.
There's a big opportunity cost, in not being prepared financially, or in not being willing to relocate etc.
Obviously some people can't afford a house/ deposit, and have little chance of saving up three months earnings, so they get doubly punished by not being able to take other opportunities as easily. The same as if you have money, it's much, much easier to get a better return on what you do have, as you have a lot more flexibility.
I read somewhere once that if you earn 30k, you should expect to have to wait 3 months to get a new job which is better than your current one. If you earn 100k, then that might be 10 months etc. I don't expect those timescales are as long at the minute, but I supposed it depends on the industry and role.
