First, GDP still doesn't count you making your own meals. Second, when eg free Wikipedia replaces paid for encyclopedias, this makes society better off, but technically decreases GDP.
However, having said all that, it's remarkably how well GDP correlates with all the goods things we care about, despite its technical limitations.
While GDP correlates reasonably well, imagine very roughly what it would be like if GDP growth averaged 3% annually while the overall economy grew at 2%. While correlation would be good, if we speculate that 80% of the economy is counted in GDP today, then only 10% would have been counted 200 years ago.
If you wanted to, you could look at eg black market prices for kidneys to get an estimate for how much your kidney is worth. Or, less macabre, you can look at how much you'd have to pay a gardener to mow your lawn to see what the labour of your son is worth.
* Get a sample of 100 random people or so
* For each person, have them track their time
* For each thing you have them tracked doing, estimate how much it would cost to get someone else to do it
But it pretty quickly gets difficult around questions of entertainment. If I go dancing for fun, should you count how expensive it would be to hire a professional to dance in my place? If I woodworking or knit for fun but then I also give away the things I make to my friends as presents should we count that at market value?
Not just question of entertainment, but also personal hygiene.
(Not saying this is a good thing.)