My main is my Warlock i402 right now, and his Renown is pretty low still, as I never do anything for Renown, all I do now is run M+ keys, typically from M+7 through 12, and the weekly World Boss and any WQs that might be upgrades. That's it.
I don't give a crap about Renown, and will not actively pursue getting it higher, because it's boring AF, to run quests for that, and is meaningless to me.
My alts are mostly level 70, some still in their 60's, and the 70's are anywhere from i350 to i370, and I just don't have the energy to really push them higher and don't care.
I hate the multiple currency crap yet AGAIN and this upgrade stuff, spend 700 Valor Points to upgrade your gear like 5 iLvls's LOL F that. All these different currencies to buy this or that, which is already outdated gear anyways at this point if your running M+ or Raiding. heck, even World Quests offer better gear or about the same as the currency stuff you can buy.