I don't think $50 an hour is a reasonable salary for consulting period. An experienced/senior developer working full time for a company with benefits in a cheap area should still (off the top of my head) probably be looking for at min $100,000 to $120,000 yearly salary (roughly $50 an hour). Depending on the situation you might be able to get more than that, I'm sure I could find people who would tell me that my estimation is also low. It is a very low salary for developers living in San Francisco, but let's leave that area out of the conversation for a second since it's something of an anomaly.

When you consult/contract, you are now paying for your own health insurance, your taxes are now more complicated, you are paying for most of your own gear, your situation is more complicated and your work is short time, you don't have the same level of job security, you are more self-directed, and you are taking on a greater amount of responsibility for the success of the project you're working on.

You need to charge more for consulting work than you charge for normal full-time development.

And all of that even ignores that at the point you're doing consulting work, you're doing it because you're likely a domain expert. A full-time domain expert in a company should be making way more than $120,000 a year, and similarly should be charging even more for consulting work. Contractors undervaluing themselves and choosing to charge too little is a pretty big cause of burnout and failure for people who are trying to get into that kind of work. I would not entertain for a second a $50 an hour rate for contracting work even if I lived in a rural area with cheap housing.

Everyone's situation is different, maybe there are people who can make that work and it makes sense for them, but on average people undervalue what their salaries should be when contracting. The overwhelming advice that I hear from contractors is "take what you think is fair to pay yourself and at least double it to get your minimum rate." Huge cause of burnout for people who get into self-employment, they give away their work for too little and then can't keep up because they're over-stressed and overworked.