I expect that the percentage of politicians and public services/institutions who have even heard of xcancel is incredibly small.
The real way to combat this is to write to your representative. The best way is probably to ask questions about something you care about, and when they reply "I've posted about this on X", tell them you are unable/unwilling to use that platform, and as a government official they should not be using a closed service as the sole means of communicating with constituents.
Of course, that probably still won't work, since politicians are lazy, and most care more about fundraising and getting re-elected than doing their jobs, but it's probably the best you can do.
> The real way to combat this is to write to your representative.
I always kind of chuckle at this advice. Is there any case of a representative changing their mind on an issue because someone wrote to them about it? I've written to representatives in the past and you are always going to get one of two outcomes:
1. If you are writing in support of something the representative already agrees with, you'll get a form letter back saying: "Thank you for your input. Representative Jones fully supports initiative X and is fighting to enact it in Congress!"
2. If you are writing in support of something the representative disagrees with, you'll get a form letter back saying: "Thank you for your input. While your input is valuable, Representative Jones is adamantly against initiative X and will not be supporting it in Congress."
I think of lawmakers as unchanging boxes of fixed beliefs and you only get to vote for and change the contents of that box every N years. The real way to combat this is to elect representative who already align with what you want.
My experience of being on the other end of this is quite old (2001-2002) but I doubt the fundamental dynamics have changed.
There are some things for which your representative absolutely has a fixed vote, either because they personally have a strong view or because political constraints (district demographics, internal party pressure, whatever) are significant. For other things, they will likely pattern match against their broad inclinations (for free trade, anti taxes, for green energy, whatever) at least as an initial position. For many issues, though, your representative probably doesn't care much at all, by default.
But the ways things move from the second or third boxes to the first are pressure (enough voters/co-partisans/whoever caring makes inaction politically expensive), money (election campaigns cost cash and so cash buys attention if not actual votes on legislation), or convincement.
If enough people write on some esoteric subject someone in the rep's office will notice, because tracking political issues is part of their job. Staffers help shape reps' policy positions and voting behaviour, at least in part because reps are too busy to pay attention to everything that comes up. And if the campaign is big and noisy enough that it threatens to become a major electoral issue then that will also force a decision one way or another. So it is possible to influence positions and behaviour, but not on every issue and very likely not if you're doing it alone (and don't write large cheques).
You'll definitely get a form letter for anything they have a form letter for, though. And even without then the actual letter is likely written by an intern or junior staffer (or I guess GAI these days). But then when I was reading incoming mail most of that was form letters and pre-printed campaign postcards too, so it was difficult to feel too regretful that the replies were mostly mass-produced rather than artisanal.
Well, there's one or two more ways, but I think it's illegal to even say them.
Politicians are lazy, sure. I also believe that hearing sustained and prolonged resistance to X as a communication platform will make a difference. It's real grassroots effort.