Your primary insurance amount (PIA) is the benefit you will receive at your normal retirement age (67 for those born in 1960). It is calculated based on your inflation adjusted average monthly earnings over the highest paid 35 years of your career, and it consists of three separate amounts: to wit, 90% of the first $1024; 32% of the amount between $1024 and $6172; and 15% of the amount over $6172 (this last amount is sometimes called the second bend point).
Let's assume that you are just at the second bend point right now, so your inflation adjusted average monthly wage is $6172, and you have exactly 35 years of earnings. So your monthly SS benefit at 67 would be (0.9 x 1024) + (0.32 x (6172-1024)) + (0.15 x 0) = $2569 per month. Now let's assume that in 2022 you earn and pay SS taxes on the maximum social security covered wage of $147,000. That is $12,250 per month and it will increase your average monthly wage by (12,250 - 6172)/35 = $173. Your PIA will increase by $26 per month (173 x .15).
To summarize, if you are at the second bend point and you max out social security wages next year, you increase your benefit by $26 /month or $312 per year. Obviously, if your average monthly earnings were over 6172 ($74k per year), the benefit of that additional year would be 15 cents less for every dollar over the second bend point. And if you earned less than the max social security amount of $12,250/mo ($147k per year) in 2022, it would be 0.4 cents per dollar less per month.
You can tinker with the average monthly wage and the amount you expect to earn in 2022 and see how that changes at various points. But the bottom line is that once you get 35 years in, additional years do not really add much to your benefit.