The remuneration package offered by a business is typically dictated by the business sector (competitors) so saying "I've worked non union jobs and I'm pretty sure the benefits I get are not directly due to a union." is faulty logic. If half the shops are union shops or competition for staff is fierce then pay/benefits will reflects.
Unions gave us 40 weeks (as opposed to 60+), no child labour, work place health & safety (maybe not such a big deal in tech but in other industry it's critical), etc... yes, government legislation made them law but unions applied pressure to get it done. While many aspects of unions have, or appear to have, outlived their usefulness they are still a very important tool in the employer-employee relationship.
Look at it this way, if unions were really just about the money then employers wouldn't care so much and attempt to keep unions out of their businesses (sometimes illegally). An employer could just say to the union "this is how much I have to spend on labour, how would you like it budgeted" and call it a day cause at that point it's just deciding on how big your slice of pie is.
I guess I sound like a union fanboy, which I'm not, but we shouldn't discount the very real impact and ongoing influence unions have.