Send your team a three minute survey. Get back what is really stopping them, in their own words, rather than what they would say in a team meeting.
Most teams are not stuck for the reason their manager thinks. The honest answers are usually some mix of not knowing what it is good for, not knowing what they are allowed to type into it, and quietly worrying it is being brought in to cut jobs. None of that comes up in a one to one.
Nothing identifies who said what, which is the only reason the last one gets answered truthfully.
The free text answers are the ones you will actually read twice. They come back to you word for word.
Responses carry no name, no email and nothing that ties an answer back to a person. Your team can see that promise on the survey page before they start, which is the point of making it.
Your email is kept so the results link can be sent to you and so Mark can follow up once. It is not sold, and it is not passed to anybody.
If you later run a workshop, this survey is what it opens from. The barriers that come back are the ones addressed in the room, so the hour is spent on what is actually stopping your people rather than what usually stops people.