You're conflating several issues into one. Many lawyers do charge a retainer (an up front fee to get started). The amount of the retainer depends on the complexity of the case, the experience of teh lawyer, etc. The funds on retainer pay the lawyer's fees (what you're calling billable hours), and when they're exhausted, if the case isn't done, the retainer has to be replenished.
The retainer is our assurance that we get paid, sort of like a landlord charges a last month's rent deposit. Law, like anything else is a business. I've never charged a 20k retainer. I have charged 5k and had no shame in it. If I'm going to spend countless hours researching a complicated matter that you can't deal with yourself, appear in court, file papers, write briefs, develop arguments and stay in constant communication with you about all stages of the case, yeah, I'm getting paid, honey. Neother I, nor my paralegal nor my assistant work for free. The lights and office aren't free. I have to eat too, sorry, not sorry.
Do some lawyers overcharge? Fuck yes! So, move along down the road. It doesn't take a big firm hot shot to handle every case and rates vary widely.
That being said, no lawyer I know charges an hour for 15 minutes. It's not a parking lot where we say "250 per hour or any part thereof." We billed in 6 minute increments. 10 of those make up an hour. So, if I talk to you on the phone for 6 minutes, I'm charging you for that call and it's going to be 1/6 of my hourly rate.
As for taking 30% of your"legal winnings," what you're referring to there is a contingency agreement. A lawyer does not take a retainer up front on those cases; that's the entire point of a contingency, no money is paid until the case is resolved. Fees are not just made up by the lawyer, there are strict rules about what percentage can be charged. They vary across jurisdictions. In mine, it was 25%. Expenses are what we call disbursements, and there are standard charges for that as well. Never heard of anyone charging a management fee ever.
If a lawyer charged you a retainer and purported to have a contingency agreement with you, that's a very bad thing and that person needs to be reported.
So, while your point is well taken, access to justice is indeed expensive, it wasn't the point of my story, nor was I asserting that it was. So, ya know, gimme a break because what you're saying just isn't accurate. It's not even close, but when you're not in it, how would you know how it actually works, right?