Not remotely comparable. You have to qualify for EI, which is self-funding, and welfare. A guaranteed basic income could simply be applied for. You can't be rejected because you don't feel like working and want to party. And when we combine this with the numbers of jobs likely to be eliminated by automation you're talking far greater numbers than welfare or EI, quite possibly a third of the population or eventually even half.
Welfare and EI are two kinds of government assistance that could be scrapped if a GBI was introduced. OAS is another. Long term disability is another. There are perhaps more.
As well, there are other potential savings in scrapping numerous tax deductions that would be irrelevant if a GBI existed. As well, each of these income supplements has administrative costs and fraud prevention costs associated with it, which would become irrelevant. There are savings associated with scrapping existing government assistance programs that would help pay for GBI.
As well, I think we have differing ideas on how "basic" a guaranteed basic income would be. You seem to be anticipating that people with a GBI would be living comfortably enough to spend all their time partying or loafing around. I think most of us are picturing something a lot more "basic". The lifestyle of living on GBI alone with no additional income would be motivation enough to get people to find ways of supplementing their income.
"Precarious employment" is increasingly the new norm in our economy. People have no job security and no assurance that their job will even exist in a few months. People like Mitt Romney talk of "creative destruction" as old unnecessary jobs are eliminated and people transition to new things. "Precarious employment" is the reality of that "creative destruction"... people drifting from one temporary job to the next as they try to re-establish a career after their old career became obsolete... people working as self-employed contractors who may or may not have a client from one month to the next... people trying their hands at entrepreneurship by selling their hand-made goods on Etsy, all kinds of things like that. If "creative destruction" is a great thing for the economy, then we need to find a way of sharing the benefits of that "greatness" with the people who are displaced by all of this "destruction" while they find new ways of "creating".
You're assuming that the automation would save 100% of the cost of the jobs eliminated, which is just not going to happen. The machines are going to cost money to buy, or more likely finance, and money to operate and maintain. You'll be lucky if the cost savings amount to 30% over salaries.
The amount of work employers have put into offshoring jobs or automating them makes it clear that there is a big financial motivation in eliminating jobs.
Ultimately every employer wants to reduce costs and increase profit margins. The wider social costs aren't part of their business model. Their business model is build around having customers, of course, but it's an article of faith that displaced employees will find new better jobs somewhere else and keep buying products. But every other employer is trying to cut costs too. As the potential means of eliminating more and more jobs are created, the assumption that there'll always be customers is increasingly questionable. If nobody is hiring humans anymore, who is going to buy your products?
-k