Talking of the supermarket, the 300 on food is going to be used there but, that is a conglomerate (in Finland it is essentially a duopoly) with shareholders who for the most part are also unlikely to be the workers at the supermarket.
Just a sidenote: those two conglomerates are co-operatives (S and K groups). If you take part in their loyalty programs, then you are like a shareholder.
But yes, I wholeheartedly agree that UBI is the way to go. Unemployment benefits and every other type of benefit alternative to them such as minimum pensions should be replaced by universal basic income equal to them. Other, means-tested benefits should remain only to the extent they exceed UBI. As you write, we could get rid of a lot of red tape and save money. Also, it would be easier for many unemployed to improve their lives by taking a part time job or starting a business without having to fear losing benefits abruptly and unpredictably.