One comment on this is when you leave a company is customary to give your two weeks. Companies rarely offer than consideration for employees. This unbalanced power dynamic is even greater as a layoff doesn’t mean a catastrophic situation for the company but for the employee it often is. The two events shouldn’t be compared apples to apples.
Define small business, because unless you are talking a mom and pop shop, my experience is severance is still a thing and definitely not big tech exclusive.
Any company under 50 employees, which makes up 85% of American businesses. And even bigger companies outside of tech usually give really small severance. Tech is basically the only area where you get 3-6 month packages for a standard lay off.