Any plan for retirement has to start with an individual's situation, rather than rely on a generic rule. For example, does the person have a pension or not? What is their risk tolerance? How much social security do they have coming? What are their spending needs? What is their desire for leaving inheritances to kids? There are also macro questions, such as the current state of the stock market, its valuation, bond rates, etc. Based on the answers to all of these questions, and others, you can arrive at the right mix of stock and bonds.
The simple model people have followed for years without fully considering some of the questions above is a 60% stock 40% bond portfolio (or 35% bond, 5% cash). That model has worked out pretty well overall through the years. People constantly declare the 60/40 model is dead, only to find it performs reasonably well. Some people drop stocks down below 60% and create a "bond tent" to reduce a risk called sequence of returns risk. That is where the stock market tanks for many years at the beginning of retirement. In a 60/40 portfolio, your odds of running out of money go up if you start retirement with several years in a row of negative returns. A bond tent reduces that risk.
Some financial advisers these days are recommending 50/50 or 40/60 because stock market valuations are very high and bond rates are attractive. Some will recommend annuities. I'm not a fan of those at all except for very specific situations.
Some people go to 70/30 or 80/20 because they are comfortable taking the risk. Or, they need higher returns to cover their spending rates. They don't have a large enough retirement nest egg that throws off enough returns at 60/40 so they are forced to take more risk.
It's probably worth talking to someone and getting some feedback on your situation, or doing internet research to figure out the optimal strategy for you. If it makes you feel any better, I'm pretty knowledgeable about investments and finance and it still took me 2 years into retirement to finally build the investment model that I was most comfortable with.