It's currently at 6,327 signatures; it needs 3,673 more for the government to respond and 90,000 more after that for a debate to be considered.
Letters to MPs almost always result in a brush-off too but they do take notice of them at least. Very occasionally you do get a non-template response too.
The one I remember where they didn't do that was when I wrote to them saying that Ordnance Survey's maps should be free, and that did actually improve! They're not totally free not but they are much freer.
And the worst response I've had was the most recent when I wrote about the UK's insane criminalisation of term time holidays, and they wrote back assuring me that they were doing everything they could to deal with COVID??
Even so, still much more effective than petitions.