Do employers actually know or care about lying on resume?
The current system of job seeking often requires to lie on resume. It is even being highly recommended by people that coach people for job seeking, although with some moderation of course.
Why do you think it requires you to lie? If you're lying on your resume it's (I can only assume) you are not actually qualified for the position you are applying for. I also assume that you are at more of an entry level in terms of your skills/qualifications. Is that accurate?
If you have success with that strategy good for you, but I'll caution others - as you get further in your career, interviews get longer and more in depth. If you say you know how to do something, you are often asked technical questions on that thing, or in-depth questions on how you'd implement that thing/skill/strategy/into the position. As others have said lying and embellishing are not the same thing. You can oversell your skill to a degree, but be prepared to need to put in extra work (probably off the clock and in your own time) to get yourself to the skill level you said you had. You may not need to! But in some positions, you may be RELIED on for that skill you're not as good at as you said you were.
Also - UPDATE your resume and keep it current. If you learned a new thing and can do it, put it on there before you forget you did it. Also, prioritize. Remove old things from your resume as you get further into your career and those skills/accomplishments are less impactful or Relevant. Replace with newer things. Keep track of what's going on in your field and stay up to date with buzz words and topics and be able to speak to them even if it's not your area of expertise.
Because you are at a disadvantage against those that do? I guess it depends on how definition of "required" and I feel like the context dictates the definition of "required" to be "required to be competitive."
Job listings often list unrealistic or impossible qualifications (such as 10 years experience in a programming language that's only existed for 6 years, most famously), overblown or unrealistically wide scope (must be expert in Linux, Windows, Cobol, C++, Atari, and to do the Kessel Run in under 12 parsecs), etc...
So to actually get a job you may be perfectly qualified for, it's requires lying. The trick is knowing what's bullshit on the job listing and what's important, and if you are qualified for a particular position, you should know what parts are bullshit. Lying in that instance seems fine to me.