Middle class people saving 1.5% on retail purchases is not going to ignite a class war. I get like $40-50 a month back, $600 a year isn’t going to change the life of someone that makes a third of what I do.
We’d all be better off without credit card rewards and paying 2-3% less for everything but it is what it is.
You don't need a tech salary to get a rewards card. What's stopping you from getting, e.g., a Wells Fargo Active Cash, Citi Double Cash, or SoFi Unlimited card? They all give 2% cash back on everything. And if you have no or bad credit, there are even debit cards that will give you cash back, e.g., PayPal Debit will give you 5% back on a category of your choice (one of restaurants, apparel, fuel, groceries, or rideshare/transit).
10 years ago I signed up for a 1.5% cashback card with Capital One, I had a 550 credit score and was making $15/hr. I also make less than $100k a year today.