No, such argument is whataboutism. Bigger problems do not invalidate smaller ones.

The only case where your point would matter is if we could only fix one or the other - human- or cat-induced damage - but that is not the case. They can be addressed independently and in parallel.

I like cats though...

No, that's not what whataboutism is.

Whataboutism is if someone says something like "Oh, yeah well, we have a bigger problem - humans kill more, so who cares about cats?" No. I'm literally saying that when it comes to cats killing birds, there is no problem. There's no radical ecological devastation happening. There's nothing to fix.

What is happening is that the number of birds killed by cats is emotionally large, such that humans interpret it as a problem, because big numbers are scary. "Did you know cats kill close to 4 billion birds every year? That's awful! We have to do something!"

"Did you know that spiders kill and consume 600 million metric tons worth of animals every year? That's awful! That's more meat than humans eat! We have to do something!" Except, we don't, because no matter how scared you are of big numbers, their presence doesn't mean there's a problem.

Similarly, with cats, we can maybe make their bird-killing sound even scarier by framing it like the spiders above: "Cats are killing 1 million metric tons worth of birds every year! Birds are doomed! We have to do something!"

Big numbers scare me too, especially the spiders one. 600 million metric tons is a lot of meat. Four billion birds sounds like a lot. But are these problems? Don't think so.

However, the cats differ from spiders.

They wouldn't exist in such large masses if they weren't bred and fed by humans.

So, there is at least the argument to make, that if we didn't hoard so many cats, the naturally occurring ones would probably kill less birds.

The numbers they have to kill to be a problem are not billions, but hundreds. Some years back, the European Turtle Dove was estimated to only have 135 breedable pairs left in the entire country of Denmark - the approximately one million house cats in Denmark would only have to kill just 135 birds to make that one go locally extinct at that time.

Four billion birds isn't a lot globally, but cats aren't hunting geese or swans - the number to compare to is the number of prey-sized birds in a local area where they can be hunted by outdoor or feral cats to notable population drops or local extinction. You might just see "a bird" or "a dove", unaware that it's one of several dove types native to your area with few remaining individuals.

Cats are particularly effective/aggressive predators in that they hunt and kill for fun, without interest in eating the catch. This makes their impact much greater than it needed to be.

Now, you can then argue against that conservation is necessary - animals outcompeting each other to complete extinction is normal, and we also hypocritically domesticate animals and take them out of their natural habitats - but it is something we generally aim for by protecting species in decline, actively controlling and fighting invading species, and attempts to reintroduce locally extinct species, and we tend to use any deviation from the status quo as a measure for environmental health.

They're not a deflection, the domesticated cat is in fact one of the incalculable harms done to the environment by humans. They're an extreme environmental problem that humans created and are solely responsible for.

The topic is how much damage is done to birds by energy production methods (even more specifically, wind vs oil & gas), not by all things. Cats are a deflection from that topic.