Anecdotally, LC interviews are hardest when you're mid-career and get easier over time. As the main difference between a junior engineer and a mid/senior engineer is whether they can work autonomously, and an engineer with 3 years of experience rarely has good datapoints for invention/difficult projects. The only way companies have found to differentiate a strong hire from a no hire is by asking harder leetcode questions and expecting perfection.

As you get to more senior levels it seems like companies still expect you to do passably well on those questions - but make their decision based on other data-points such as impact/past projects etc.