>Benefits can almost always be compensated for with more money. 401(k), heath, dental, paid time off -- all of these things are just another form of compensation.
The thing is that some of these are worth much more than their transformation into a raw dollar value. As someone who has just recently transitioned from primarily self-employed to primarily corporately employed, the ability to take a day of PTO at basically any time has been amazing and no amount of raw dollars can compensate for that ability (except as these dollars are deployed to arrange affairs such that others can assume your responsiblities at the drop of a hat, but this takes more than raw dollars). I can also say that health insurance is worth more than its face value -- health insurance is an admission ticket into the doctor; if you have an insurance policy, they'll give you everything you want and treat you well, and if you don't, they'll demand large sums of cash on an almost-daily basis to continue to provide for your medical needs. If you have an astronomical amount of money maybe this isn't a concern, but most people not making double-digit millions per annum are going to find it difficult to cope with self-pay rules for any significant medical work.
>If you're able to stash enough of a buffer to cover you during that period, then you have just established security.
Security doesn't really work this way either. As an employee, you have an implicit sense of perpetual security. As long as you continue to provide the base value you were hired to provide, you will, in general, continue to collect your paycheck indefinitely. Getting paid in perpetuity is MUCH more secure and less stressful than watching your six months' worth of saved money tick down, especially if major or unexpected expenses occur.
Though I did well consulting full-time for the last five years or so, my wife and I were always worried when it came time to make big purchases and would often opt not to do so, since we'd never know for certain when our next chunk of money would come in. Since I've switched to employment by a corporate entity, we've felt much more comfortable making these necessary purchases and have been trying to clear our backlog of major stuff needed (appliances, vehicles, etc.).
It's more than just money. There's a peace of mind and freedom from stress that comes with corporate employment that can't necessarily be mapped onto an [attainable] dollar value.
Everyone wants to cross the chasm to independent wealth, but they don't understand that the process of doing so can be extremely onerous and stressful. As for me, I haven't given up yet, but it's not a pleasant experience.