When it’s good, it’s my second favorite genre, so I consume a lot of it. Sadly, it’s mostly bad. Most of the time, it’s just a crutch for the author to explain the world to the reader/watcher in modern terms and as blatant self-insert pandering. It’s very seldom that the isekai aspect has actual ramifications on the plot. Most isekai would just as well work as a fantasy where the main character just so happens to be born with a special power.

As for good examples, I would recommend Ascendance of a Bookworm. I have problems with the anime adaptation (a whole different can of worms, and once I start, I won’t stop again), but it’s the opposite of a power fantasy (she nearly dies from climbing a flight of stairs), and her modern-day knowledge is her only superpower and her motivation.