Why are people suggesting Azithromycin with HCQ to cure coronavirus???
What is the benefit, why do people feel the need to add Azithromycin???

https://www.drugs.com/medical-answers/antibiotics-kill-coronavirus-3534867 WHO: antibiotics don't work against viruses, only bacteria & yet healthcare providers are using antibiotics in some patients with COVID19:
Although reported to be uncommon early in the course of COVID19 pneumonia, a secondary bacterial infection can develop and may need to be treated with antibiotics
If treatment is required for a secondary bacterial infection then antibiotics can be used: penicillin (ampicillin plus sulbactam [Unasyn], piperacillin plus tazobactam [Zosyn]), macrolides (azithromycin), cephalosporins (ceftriaxone [Rocephin]), aminoglycosides (tobramycin) & glycopeptides (vancomycin [Vancocin HCL]) Often a combination of 2 antibiotics is used.
Azithromycin may have antiviral & anti-inflammatory activity & may work synergistically with antiviral treatments. In in-vitro lab studies azithromycin has demonstrated antiviral activity against Zika & rhinoviruses, which cause the common cold.