I would search for & read some reviews recommended modems for AT&T DSL .
There probably is a better one.
I had AT&T DSL a long time ago .
I am in town so I got the paid for speed.
This may not work for you & AT&T may not offer this any more.
I dropped my landline but kept DSL.
This allowed me a dedicated DSL line with no filters needed.
This did get the speed to the max paid speed fairly constantly.
I went to cell phone only for a while.
Then I went to VOIP with Skype.
It worked OK since I didn't video Skype.
I have cable now & I use an OOMA Telo for my VOIP.
I believe it will also work with DSL.
I doubt the Firestick will ever stream well with DSL.
I dropped any satellite or cable TV .
I have a good antenna & get my TV OTA.
For YouTube.
Download with a downloader .
Then play with a video player on your computer.
I use this downloader: Just keep using the free starter version.It works well for most things.
https://www.4kdownload.com/products/product-videodownloader
VLC is a good media player that will play most videos.
It works a lot better than WMP.
