When people hear the word "ToS," they often think of a long PDF file that would take a lot of time to read. In reality, we don't need to read the entire ToS; we just need to read a few important points, such as deposit terms, withdrawal terms, and the welcome bonus. The minimum deposit amount for each network and coin type varies. The minimum withdrawal requirements and fees apply.
They forget about FAQs that is a brief version of ToS which is helpful too. With ToS, they don't need to read all texts in the document and they can save their time by using some key words for searching most important terms in ToS about account, deposits, withdrawals, KYC and restricted areas if any.
All basic but vital terms about account and fund must be read in ToS, as it is a very important preparation step before actually funding an account with your money and using it for bets. Reading all ToS is while cumbersome and time consuming but scanning it with keywords is less time consuming and very doable.
Finally, there are the rules regarding the welcome bonus. Personally, if you don't care about your money and withdrawals, you can use the welcome bonus. However, if you want to withdraw after winning several times, I don't think you should activate the welcome bonus.
If people don't scan FAQs and ToS, they will almost not have time and habit to read rules of any promotional program. It is not problem if they don't win, or are not eligible to claim any bonus, but it will turn to be big problems if they have kind of actions are not tolerated by the program rules.
So spending some time to read a promotional program's rules is important and almost mandatory before joining.