We are considering a side trip from Mexico City to Teotihuacan. I have arthritis and stairs can be a challenge. Is it worth the trip if one can't climb to the top of the pyramid? How crowded does it get and in general what is it like and do you recommend it (we do enjoy visiting ruins, historical sites, learning about ancient cultures, etc)

I've been to Teotihuacan three times and only climbed a pyramid once (of the Moon). Yes, there is a fine view but there is plenty more to keep your attention. Do not miss "The Citadel" and its magnificent Temple of Quetzalcoatl. Do expect to be accosted by peddlers, etc.

When we went to Teotihuacan in 2019, visitors were only allowed to climb a small portion at the bottom - not all the way up to the top of the pyramids. A quick internet search suggests there is no climbing allowed now. We spent three or four hours there and found plenty else to see and explore. Our visit was in November, and I don't recall it being all that crowded.

fantastic, thanks for the insights