We no longer have the means of capturing the HST, nor the capacity to deliver and install updates to it.
-Wolf sends
We do have the parts we need to do this, they're just not all together and some aren't quite there yet. But it's close enough to be a definable problem with plausible solutions.
Hubble has an IDA compatible docking plate left behind on its last service mission for the possibility of Orion or Starliner (I think it was still being called Orion Light then) coming back later. Dragon could dock to this but would block it's EVA port to do so, but a matching plate mounted in the trunk has been proposed to work around that.
The Dragon trunk large enough to carry most of the serviceable parts like gyros. It won't do for a major overhaul like was needed to fix the main mirror but Hubble doesn't need work like that anymore.
Polaris Dawn showed that in principle the vehicle can handle an EVA and the suits can handle the work. The open cycle life support system fell short but isn't meant to be used in a live mission.
Starliner is not EVA capable, Orion will likely never see orbital use like this, and crewed Dreamchaser's (it it ever flies) capabilities aren't known yet - it might end up being perfect or entire unable to even try. But Dragon has a clear path to walk.
Now the wet blanket, to be fair: Polaris Dawn showed that Dragon can handle the work in principle, but also that in practice it is still lacking in key ways that must be solved, and even previously solved problems can carry all kinds of surprises the second time. And Hubble, even on its last legs, is still very important. By no means do I think Hubble should be Dragon's first live service mission, and by no means should the mission be attempted at all until Hubble's successor is already operating, because barely having Hubble is better than having nothing. But even reduced to the third string by James Webb and Nancy Grace Roman, observation time is a deeply limited resource and there will be lines down the street to use Hubble as long as we can keep it going.