A catact can definitely change how myopic or astigmatic your eyes are. Some people see almost no change, in my case my problem eye went from -0.75D of astigmatism to -4D, then the astigmatism faded and instead the myopia went from -9D to -19D before surgery (which I postponed since my other eye remained 20/20 correctible and my brain just tuned out the bad eye). Even that initial astigmatism may have been the cataract, or merely abnormally high lenticular astigmatism, since postop I wound up with 0D of astigmatism in that eye without anything done to correct it.
Your eyes essentially have the equivalent of a bit of monovision due to the astigmatism. Astigmatism means that your eye has different lens powers at different angles, and since you have 0 sphere in both eyes, that means at least one part of the eye in each case is focused well at distance, but the astigmatism in your left eye is enough to blur things at all distances a bit. The other angles of your eye focus in further, in the left eye's case part of it focuses in as far as -1.75D which is the equivalent of +1.75D readers, though its average focal point (half way between the two) is less. Your left eye has a spherical equivalent of -0.88D (sphere + cylinder/2) which is like having +0.88 readers.
What matters is its impact on vision, not its grade which is based on its appearance. it seems its impact can vary quite a bit depending on its location and the person.
In my case I had a puzzling situation in the opposite sense. My best corrected visual acuity in one eye dropped from 20/25 to 20/60 in only about 3.5 months, but my optometrist didn't see enough of a problem with the lens to think the issue was a catarat and referred me to an ophthalmologist to diagnose the issue. On the referral she merely referred to it as "trace nuclear sclerotic changes", and the ophthalmogist diagnosed it as a cataract (which eventually became more noticeably obvious to the optometrist before surgery).
Usually most government and private health plans don't cover surgery until visual acuity is worse than 20/40 or whatever the driving standard is. Some places I gather are starting to become more flexible and will cover surgery if the cataract is in some other way interfering with visual function in a major way. For instance even some people with good visual acuity with a cataract during the day have nighttime visual symptoms like reduced contrast sensitivity or visual artifacts from headlights that impede their ability to drive.
Cataracts usually develop very slowly, mine was very atypically rapid, in addition to causing trouble at the atypically young age of 49. So there is no way to predict how long it will be before your vision degrades to where you'll wish to get surgery.
One advantage you have over many patients is still having good visual acuity so you might consider doing some research now to decide what to do when your eyes bad enough that you are ready for cataract surgery. After you have surgery, most IOLs don't accomodate at all, your eye loses the ability to change focus. The default lens covered by health plans is a monofocal lens, which when set for distance is like the level of presbyopia of someone elderly. Results vary, but I've seen doctors often suggest you should be prepared for vision to start to get blurry around 6 feet inward, though some tiny minority can do a bit of reading held out far, while others have posted about having vision start to get blurry around 10-12 feet. To balance that issue, some people get the IOLs implanted to provide monovision, one eye focused nearer in. The level of monovision people adapt to differs, but larger amounts of monovision are harder to adapt to since the brain has trouble merging the images and depth perception is reduced since its mostly using one eye for each distance.
Other people get premium IOLs they pay for out of pocket which provide better vision at a range of distances, e.g. multifocal, extended depth of focus or accommodating lenses.
Since you have good visual acuity now, you could consider doing a contact lens trial to test what level of monovision might work for you, or try multifocal contacts to see if that sort of correction might work for you. Even if you normally don't like contacts, it might be worth trying them temporarily to decide what sort of permanent correction you'd like after cataract surgery. (and if you haven't tried contact lenses recently, they are more comforable than they were a decade or two ago). They aren't perfectly accurate tests since the optics of multifocal IOLs is a bit different and better so you might like them even if you don't like multifocal contacts, but it might give some clue what its like. I liked multifocal contacts better than monovision since I noticed the improved depth perception, but many people don't.
I don't know your age, but you likely have a larger degree of accommodation left in your eyes than you will with a monofocal IOL so even the monovision test isn't completely accurate, but it'd give you some sense of things (better than your imperfect monovision you have now without correction).