Chess engines, puzzles, and ELO rating

I noticed that getting a higher fake ELO rating with puzzles, it is very much about being efficient and solving a lot of puzzles at a lower level, and occasionally you are able to solve a puzzle at the rating that you are estimated at.

My question is this: when I play my computer and set it to 1800 or 1850, does that mean it simply doesn’t make the mistakes anymore that you need the knowledge of a 1750 or lower ELO rating for you to be able to solve them?

I’m under the impression that if I want to get better, I really need to focus on playing chess against the computer at lower computer ELO ratings, knowing that I can easily beat the computer, but I need to become more efficient at not making any mistakes. I just need to spot my own also, which I usually do immediately after the move I made. How do you see this?