I like the stalks and I'm not sure why the frozen broccoli you buy does not contain the stalks. Many don't like the stalk so this may be a reason for not including it.
The following article is an excellent article on broccoli but do focus on the summary titled 'reality check'.
https://www.thinkingnutrition.com.au/broccoli-bad-for-you/I now have my own sizeable veggie garden so I'm growing many cruciferous vegetables such as broccoli, cauliflower, kale, cabbage, Chinese cabbage, bok choy, tatsoi and radishes.
Assuming I have a reasonable harvest I will be eating plenty of cruciferous vegetables without hesitation. I will eat the stalks and younger leaves of broccoli.