I have been flying with Ryanair for around 15 years now, roughly 6 or more flights per year, and my overall experience has been consistently fine once I adapted to how the airline works.
At this point I have a clear routine that removes most of the stress and unpredictability:
I usually pay to select seats, typically row 5 or 6 aisle, or a window seat for longer flights over 2 hours
I mostly travel with only a backpack and always make sure it fits the size checker
If I bring a small carry-on bag, it is a hard-shell case and I ensure it fully complies with dimensions
I try to board as early as possible so I can secure overhead bin space near my seat
I use the order-to-seat option and often get coffee shortly after takeoff
I prepare entertainment in advance, such as downloaded movies and noise-cancelling headphones
I position my bag near my seat when possible so I can have more legroom
At 170 cm height, I find the seating manageable and generally comfortable with this approach
Overall, I find that Ryanair works well if you plan properly and understand the constraints rather than expecting a full-service experience.
As the saying goes, if you fail to prepare, you are essentially preparing to have a bad experience.