Another aspect would be the more money you have, the less you need money, so the easier to hoard wealth and assets and not pay taxes. Put 1 million in the S&P 30 years ago, it's about 10 million today. Give it to your heir and the 9 million gain is tax free due to stepped up cost basis. The heir would also then collect qualified dividend income, about $150k a year, at lower tax rates than someone having a job. In a few decades this could then be passed on again.
So millions are made, all at an overall tax rate of a few % and dropping. (Notice the shift to share buybacks). Meanwhile how much has the guy doing roofing in July been paying? An order of magnitude higher for hard labor. It's beyond ridiculous when you delve into the details.
These are just non-esoteric things a layman can do. Haven't even touched on more complex things or the detrimental effects of something like fiat money.
I'm aware of all of those things and have participated in several. Not seeing the big problem, honestly. Cap gains at 15-20% (plus more in some states that also collect at that level) is non-trivial. Those only earn when invested in businesses that succeed and employ others.
I was an independent contractor for a couple of years (before CA ruined that with AB-5). Never set up an S-corp, but I can tell you that it's no cakewalk being independent or running a small business. I had to pay the entire 15% S.S./Medicare rather than the usual 50-50 split with employer. While my SEP-IRA contribution limit was about 3x the 401(k) limit, I did not receive employee matching nor any bonus/RSU. To earn as much as I did as employee with those benefits I had to charge a large hourly rate (yes, I understand the fully burdened cost of a full time employee) and that all showed up as 1099 income. My taxes were not lower.
Oh, and don't forget medical insurance. At the time I was thin on cash, had a mortgage, prop tax, etc. Thanks to the ACA, insurance rates, which were already high, increased further. I decided that my healthy lifestyle made it worth the risk to go uninsured and pay the uninsured penalty for two years rather than $1200/mo in insurance I rarely used. I paid out-of-pocket for health care and usually could negotiate a lower fee because no paperwork was needed.
Stock is not tax free. Restricted Share Units, the common way to provide incentive pay these days, is taxed as income when the shares vest. When sold, capital gains (or losses) are calculated if they were held for a year post-vest, or as income otherwise (short term gain).
People accumulating wealth is not a terrible thing. The extra homes they have employ people in construction, design, and maintenance. Their "luxury goods" do the same. They pay property tax and fuel tax. If there's a legal dodge, who wouldn't take it? Simplify the tax code to reduce gaming.
I also know people in the 0.5-0.1% including one of my best friends. I've known him for 25 years. He's a few years younger than I am. He didn't finish his BS in CompSci, but is one of the sharpest SW guys I know. He's worked at a series of startups, only one of which was semi-successful. He didn't get rich there. He saved and bought his first home and a couple of rental properties during those years.
He ended up at a big tech company as a low level manager about 14 years ago. That's where he made it. He still works long hours. Has bought more rental properties (outside of CA). Likely retiring soon in his mid-50s like I did. We worked for it. We made mistakes, learned from them, and moved on. We paid our taxes and made our charitable donations, lived within the law, lived within our means. But now we're wealth-hoarding rich bastards who should pay more. Pffft.