How anyone working for 30+ years isn't worth ~$1M. It only takes like $10k/yr!!!
The opening post implies $100K is invested from Day One of the 30 year period. $10K invested per year, starting from $0, probably will take more time to reach $1M.
Open Excel
A1 =-FV(0.07,30,0,100000)
A2 =-FV(0.08,30,0,100000)
A3 =-PMT(0.07,30,0,1000000)
A1 is $100k at 7% for 30 years.
A2 is $100k at 8% for 30 years.
A3 is how much per year to get $1M at 7% after 30 years.