so not something to care about? just a service to yoink some extra sats off impatient people?

Fee estimation have nothing to do with tx accelerator.
These are not new. They were available many years ago, form the blocksize war.
Here are the remaining ones from then
- https://www.viabtc.com/tools/txaccelerator 
- https://bitaccelerate.com 

DarthCoin

if everyone launches these products how do we get good fee estimation? these are all opaque aren't they?