If I were hiring for my farm business, I would consider years of experience to have some relevance. Every year brings a new environment (e.g. drought, rainy, etc.) and, with the work being largely seasonal, it takes a whole year for a chance to try again. As each year brings new challenges, having another year of experience does strongly indicate that you faced a new challenge each time.

If I were hiring for my tech business, I agree that it doesn't mean a whole lot. One can experience a multitude of different environments before lunchtime. One can also do the exact same thing over and over. There is no seasonality to hold you back or push you forward.

Ultimately, what one is interested to know in questioning years of experience is how many scenarios someone has run through so that when something similar happens again you can believe, with reasonable confidence, that they will know how to react. This is quite measurable, but it can be hard for someone in tech to keep track of as there isn't a good frame of reference like in farming where you can simply remember each year.