If one uses such time to actually ask questions it can break the situation. The time scheduled tends to be pretty constnat and as few as 5 questions can break a 1 hour or 2 hour session flow. This is especially jarring if the director of the situation encourages questions and treats curiosity as a virtue.
If one genuinely wnat sto encourage activity form the audience it can mean that there needs to be a seesaw on how the situation goes depedning whether audience participates or not. OFten there are talk points or facts to cover and sneaking them into answers to questions that point in random directions requires a very different skill than delivering a strongly manuscripted tight presentation.
A lot of educational situations are strctured so that they are unable to reward activity on the action level even if on speech level that is lauded.