"I really wish someone would explain to me why amateurs are allowed to rivet or glue together their own airplane and allowed to takeoff."
Certificated GA is less heavily regulated than Commercial aviation. The GA accident rate is consistently higher.
E-AB is less regulated than certificated GA. The accident rate for E-AB is consistently higher.
It's a matter of where society and the regulating agency decide the trade offs should be, whether that be aviation or any other aspect of our lives. That's a constantly moving target as societal attitudes change and regulators, accountable to politicians, respond to that change.
I'll make the proposition that more regulation of an already highly regulated activity, aviation, is unlikely to produce anything more than marginal results, with a good possibility of unintended negative consequences. If the objective is to reduce the number of lives lost in the transportation sector over time, then put the effort into the least regulated part of that sector that produces by far the greatest number of fatalities. And we all know what that is.