@ProfRob's link gives some very interesting numbers.

The Arecibo dish can detect [a million watt signal it emitted] at a distance of about 5000 light years. The dish has a diameter of 304m.

and confirms the inverse square law applies.

We assume the directionality of The Dish's (or the alien's) signal is equivalent to that of Arecibo

The Dish is 46m diameter, so the detection radius drops to $(46/304)^2$ or 2.3%, for a detection radius of 113ly. A 16.7 ly (Altair) signal is 300 times closer than Arecibo's limit, so a dish can be $\sqrt{300}$ = 17.4 times smaller or 17.4m.

Of Wikipedia's List of radio telescopes a great many are bigger than that; a more important discriminant might be the frequency of the signal.

This doesn't yet answer questions of "are we routinely looking?", I think there is room to improve this answer.

@ProfRob's link gives some very interesting numbers.

The Arecibo dish can detect [a million watt signal it emitted] at a distance of about 5000 light years. The dish has a diameter of 304m.

and confirms the inverse square law applies.

We assume the directionality of The Dish's (or the alien's) signal is equivalent to that of Arecibo

The Dish is 46m diameter, so the detection radius drops to $(46/304)^2$ or 2.3%, for a detection radius of 113ly. A 16.7 ly (Altair) signal is 300 times closer than Arecibo's limit, so a dish can be $\sqrt{300}$ = 17.4 times smaller or 17.4m.

Of Wikipedia's List of radio telescopes a great many are bigger than that; a more important discriminant might be the frequency of the signal.

News has broken that we had a quick look for an hour on the 22nd August 2023, and that this was considered newsworthy. https://www.asahi.com/ajw/articles/14985246

At which point, I'd broadly estimate that a similar return message would almost certainly be lost. If this is the only time we've looked to see if there is a reply, assuming that the reply could have come at any time in the last eight years, there is a 1-in-70128 chance of detecting the signal.