>Inflation adjustment doesn't take into account costs that are prevalent in an era but totally absent in another: like internet access, cellphone bills, and such. Nor how much one not puts into their retirement account / savings to spend on daily needs.
Yes it does. Have you looked at how the BLS calculates the market-basket they use for CPI calculations? It's determined by actual spending by actual people on actual goods. This information is public:
"Knowing that consumers are constantly offered new items to include in their market basket, how do changing market baskets influence the CPI? The answer is not unambiguous and depends on the importance of the change in terms of total expenditures by consumers."