Fairly important yes. Pits in particular, although that does not necessarily mean a loose foam pit. Most gyms use loose foam but there are resi pits, air bags etc. High level gymnastics takes a big toll on the body, so pits will reduce the risk of impact injuries. When learning skills there will be crashes, having those pits is very important to reduce injuries.
I feel spotting is less necessary. We spot a lot more with lower level kids, learning their first tucks, handsprings etc. These kids are still learning where they are in the air, and how these skills feel. We do a lot of drill work for higher level skills, the need for spot is less when you have lots of equipment to set up drills, can coach creatively and have gymnasts who are well trained. I find skills taught via spot are not as well learned as skill taught via drilling.