Are jazz and blues disappearing?

No, players are expanding the forms.

No they are not. You can listen to all the Jazz and Blues you want to on Youtube. There are clubs that present  Jazz and Blues all around the country. New Orleans has been having a Jazz festival every year for about fifty years and people come from all over the world to attend this two week event.

OMG No! Just search the web. I think even more people are laying with a the youtube instructionals. 

No there are less innovations but they are still popular among more mature listeners and kept alive for younger people by school music programs that feature big band jazz. 

It’s not disappearing just receiving less national attention but it’s still the same number of acts and new music being released.

In this section almost, missing a little.

They are many genres of music, dance, art, even cuisine, that have dedicated followers - and you would be surprised at how many have legions of followers!  If all a person experiences is the crap you see on TV, or in the popular press, etc., then you are not only missing out on a LOT of life - but allowing yourself to be brainwashed.  Life is a banquet - do not settle for junk food.

Not in the local music scenes everywhere in the country. Maybe in the mainstream media.  If you take your social cues from mainstream media, you're being lied to.  Mainstream media would also like you to believe that Trump has no chance of winning in November. They largely ignore those who support him, except when they can find some crazies they can use to make it look like all of his supporters are crazies.

Get out to the local music venues - when it's safe to do so again - and you will find jazz and blues and Americana music and hard rock and classic rock and metal and anything you're looking for.  It ain't all a choice between rap/hip hop and country music.