If a CRT PCB has dark spots on the board, does that mean it's a high hour set?

[Electronic M]

There were some people who used their sets 8+ hours a day every day until it wasn't repairable or they upgraded. Some places were even worse. There's a thrift store here that used to be a large supermarket (there's one or two other businesses that have similar) and at the entrance leftover from the supermarket days is a 90s-00s era Sony consumer TV hooked to a camera that captures everyone walking in so you can see them filming you...That thing still works, and I don't think they ever turn it off...It must have an impressive hours count.