I don't know, I don't have all the answers, don't know how to thread all the needles, but it seems to me like WWE will always win (and their winning could threaten the existence and finances of other promotions) if promotions perpetually feel afraid to try to be "mainstream" simply for fear of being labled by some as "WWE-lite."
There were certain years or certain aspects of WCW where I think they weren't "WWE-lite" per se, but their own thing (can maybe say the same about TNA), and I think AEW is already its own thing thankfully, but I think AEW still can find some higher ratings and market share like WCW once had while not betraying its core vision of being a wrestling-first promotion.
I don't see how AEW finding its own version of successful audience-growing stories like (the equivalents of) the nWo or Goldberg will necessarily render it WWE-lite.