Pop musicians make almost all their income from concerts, so once a tour is planned it has to be completed no matter the condition of the performers who gradually deteriorate as it wears on.
A famous frontman might already be wealthy enough to cancel concert dates and accept the loss of income, but other parts of his team with greater dependence on tour money cannot, so despite whatever unfavorable circumstances the concert dates are met for the sake of not losing the support team that makes touring possible.
Travel is grueling, but the money earned can sustain musicians for several years until they can tour again.
Tom Petty’s physical health declined throughout the tour, not just his emphysema and knee problems, but a fractured hip that eventually broke and became the cause for his overdose of pain medication.
Fentanyl patches (strong opioids), oxycodone (opioid), temazepam (benzodiazepine), and alprazolam (Xanax, a benzodiazepine) worked synergistically to cause cardiac arrest. Opioids and benzodiazepines famously multiply effects upon one another until the heart no longer functions.
From the crowd, entertainment looks like a fun and easy job, but spectators rarely consider the pressure of bringing a show to fans in a different city every night and leaving a positive impression so there are ticket buyers next time income has to be earned.
No matter what condition the performers are in, they need to display excellence. Sometimes it’s their last performance ever.