On the retirement planning question, I found this site to be pretty helpful:
https://engaging-data.com/will-money-last-retire-early/ read the notes and play with the variables a bit.
For us, about 18 months before I retired my wife and I set up a “retirement” budget, which excluded some work-related expenses (suits) and upped some retirement spending (travel). We lived on that budget for a year to be sure we had it all thought through and ended up with an annual expense number that we are comfortable with. We did this because my job income was several multiples of my expected expenses, and we needed to be sure (when I was working we could “waste” money if we felt like it, now we are more careful) we had the expenses right.
Subtract whatever you believe about social security. Then the equation is how to get that much money every year, plus inflation and have some for extraordinary losses (deductibles, medical). And think about changes to income taxes (especially an increase in cap gains taxes).
For us the retirement number is a lot lower than the numbers others have posted in this thread. But being conservative in planning (but aggressive in investing), we saved about 20% more than we needed to satisfy the above. That ensures the accounts grow in normal years and have enough buffer if there is a big correction, especially in early years.
You can plan the retirement savings as an annuity (use the principal every year in addition to the income, with an expectation of x years until the money, and you, are gone), or as an estate (use only the income each year, maintaining or ideally growing the principal). The former allows earlier retirement if you are pretty sure of the timeframe (how long you will live), the latter is more conservative but takes longer to accumulate.
Back to the thread topic: Having enough for retirement doesn’t make me wealthy, in my mind. I call that comfortable. Having enough to never worry about it, not need to budget, and so forth, is wealthy. Jets and yachts are fabulously wealthy markers.