I've seen this go both ways. It depends on how funtional/dysfunctional other parts of the organisation are. If they're as competent as you and just asking for things they genuinely need, cooperation is great. If they're not, they turn into "help vampires" and you have to put up a firewall to prevent them destroying your productivity.
I think my current workplace suffers from too much team defensiveness + not having a CTO or equivalent to integrate across teams.
It also depends on you (and others in similar roles) having a reasonably well-tuned sense of what is reasonable and what is not. I have a fairly broad charter myself but I help out all the time with things that I could argue are "not my job" as narrowly defined. However, they're mostly at least adjacent to my primary responsibilities and are mostly not a big deal to do.
Were someone to come to me with a request that looked to have the potential to be a big time sink--or if I was getting overloaded with too many one-offs--I would definitely have a discussion with my manager at that point.
I think my current workplace suffers from too much team defensiveness + not having a CTO or equivalent to integrate across teams.