There is actually a quite hardcore history of advocacy that cropped up in the civil rights era where folk with disabilities performed some really heroic protest. The tale of Ed Roberts and the "Rolling Quads" is pretty legendary stuff.

The wins established a mostly unchallenged veiw at a legal level that differently abled people deserve to have their participation in society facilliatied. It was a major win...

But with success comes stagnation. Part of why the LGBTQIA+ is so visible is the movement is still marching and there is a secondary purpose to the movement. The visibility of actually running up a flag in those communities is a way to make something potentially invisible visible. To give a sense of solidarity. A lot of subjugation techniques of the past were to make people feel like they couldn't possibly make strides for equality because their numbers were too small. Prides are the antithesis to that form of subjugation and for lost souls cast out from their families to find a non-hostile culture. Prides are run by legacy volunteers and are huge in participation so people who want to gain political points for future votes or as an audience gathering together anyway to advertize to look at tipping their hat to the movement as personally adventageous. They don't nessisarily do it out of generosity and respect. While it's possible they do actually have aligned principles of civil rights it is basic backscratching as the LGBTQIA have something they want. Votes or dollars.

As far as I am aware Disability civil rights advocacy has moved mostly into the pocketsquare and tie political sphere rather than the rough and tumble social advocacy battles where it began and as a result the short memory of society has forgotten the impact and demands of those voices in the villiage square ring of cultural advocacy. Since fewer people are counted on to be tuned into C-SPAN then can be counted at to go paint some rainbows on their faces and participate in a mardi gras style carnival event it doesn't get the same level of attention.

In short - effective cultural advocacy along the lines of the LGBTQIA is driven by communities banding together and going out and being visible in force and making some kind of public fuss. All the better if it's an over the top fun day... Or if you set fire to things and riot that basically gets people talking and asking questions too. Basically whatever works to be the loudest squeeky wheel. Otherwise non-minority folk who don't have to think about your needs will forget to ask you what you need or straight up forget you exist.