"Could easily" is a very long way from "typically does". Coming up with $100,000 of personal exemptions and sched A deductions on an AGI of$350k would not be easy to do.
We can be mislead by the ability and tolerance on the part of board members to have very high incomes with a very moderate life style. Most families burn money, and it takes earning a lot to be able to burn enough to come up with deductions like you mention-except once in a blue moon.
A married couple earning $150k each at comoanies similar to those DW and I worked can quickly rack up a lot of deductions.
Off the top of their paychecks before taxes comes $33k for 401k, $44k if they are both over 50. Limits for defined contribution plans and SEPIRAs are similar.
$5k for pre-tax payment of company Group Health insurance.
stick another $5k into an FSA.
That's now already down to $250k taxable.
Now start on the typical deductions.
personal exemptions $6.8k for husband and wife only
State income taxes ~$10k or equivalent sum in Properrty taxes & sales taxes for those States with no income tax
Mortgage interest ~$10k on a $250k mortgage at 4.5%
Charitible deductions
etc etc.
This is just a quick a work-up based on a working couple but high spenders with 2 mortgages or a large mortgage and some dependents can get pretty close to $100k in deductions fairly easily.