app store is not downloading apps on my mac which is recently updated to el capitan

Why did you dumped all? Why do you make this unusable?

I did report it on Thursday. Apple support just recommended to open devsupport ticket (haven't heard from them).

There is any easy method to downgrade? Maybe it will be the suitable solution until the next update.

Downgrade doesn't solve the issue. It's present on Yosemite + Mavericks as well.

You have to look into other threads. Definitely not an issue of 3rd party apps 😉 It was a lame excuse to close the ticket.